With the majority of the Coalition's Naval Ships and Shipgirls at ready, not too far from Hawaii... The SIREN's Last Line of Defense has been deployed. Due to the Coalition's Saboteurs and Agents preventing them from building more Portals... Along with a successful Dimensional Stabilizer by the Future Tech Corps... They'll throw one last battle, before returning to Azur Lane's World.

If the Coalition's International Navies, Azur Lane & Crimson Axis could beat them and send them back to their world... Then, the Solaris Earth's Waters... will be forever safe... Aside from the usual predators...

"All Ships! Forward! Commence Operation Sea Champion!!!" Admiral Reinhardt of the Coalition Navy yelled on his Radio.

And all the Coalition's Warships obeyed and advanced. Along with USVs (Unmanned Surface Vehicles)

"Azur Lane! Crimson Axis! Liberate this world! Commence Operation Sea Champion!" Lawson added.

Objective I. Blitzkrieg through the SIREN lines. At least four positions on each island must be safe for the Naval Infantry and Marines to make an Amphibious Landing.

"Fire all AShM Missiles! SIREN Carriers and Battleships!" Admiral Reinhardt radios to all Coalition Ships, and they fired AShM Missiles, directed at the SIREN Battleships and Carriers. Seeing them as bigger threats.

With a good amount of Enemy Carriers and Battleships taken down by AShM Missiles. As the SIREN Jets aircraft took flight from their Carriers and Air Bases, the Coalition's Fighter Jets responded with their own.

And the World's Largest Modern Air Battle has started.

Countless Missiles and Gauss AutoCannons by the Coalition's Mutil-Role Jets sent many of the SIRENs jets to the seas, as a good amount of their own were also shot down. As the Air Superiority Jets and CAS Jets armed with Advanced Laser Lance Cannons tore through the SIRENs both Jets and Ships alike.

As the Shipgirls arrived, they quickly went on the Assault, as Destroyers went on the kill with their torpedos, the Crusiers provided Anti-Air Support for the Coalition Jets, and Carriers (Shipgirls) sent their prop planes to boost the firepower for the Coalition's Air Forces.

"Lord... May this battle lead us to victory!" Saint Louis, as she along with a good amount of Iris and Vichya Shipgirls followed.

"Gascogne. Engaging threats... And Assisting Allied Forces."

"It's all or nothing, everyone! Keep on the assault! The People of this Earth are looking up to us!" Prince of Wales added.

"Javelin, full power advance!~ Let's win this!!!"

"I will enjoy learning their weapons..." Chkalov muttered while sending for of her planes.

"My love for the Phoenix Commander is invincible! Ahaha... ahahaha!" As Akagi went unhinged and shot down more SIREN Jets...

"Sister, please take this seriously." Kaga.

"More where that came from, SIRENs! With the Coalition with me, I'm not afraid!" Georgia yelled as she blew up a few SIRENs Battleships and searched for more. As the 6th Coalition Fleet went on the supporting role.

"Heh. This is something everyone in our world won't forget easily!" Baltimore added.

As many of the SIRENs Mass Produced Ships were taken down, more came out, along with the Executor Class, Elites, and some Arbitors and Enforcers.

But it was what they needed. As the second wave of Reinforcements arrived, Aerial Warship, NPX El Alamein returned. It turns out, the New Administration has repaired it with the NPX and made improvements to it.

"Holy shit!!!" A Coalition Captain yelled.

"It's the NPX El Alamein!? I thought it was crippled!?" A Coalition Commander added.

And then a hologram of Lee Sooyeon came to Admiral Reinhardt, and she let out a slight grin.

"Consider the El Alamein are a class now."

Reinhardt checked again... And there's not one... But four NPX El Alamein, with the original one, retrofitted as a Battlecarrier. They're now the El Alamein Class Carrier (UNSC Athen-Class Carrier) along with the New Nurnberg-Class Aerial Heavy Frigates. The other two El Alamein Class were sent to help Kevin and his Operation in Makemake.

"All ships! The El Alamein has risen from the ashes as an Aerial BattleCarrier! We now have a strong fighting chance!"

With Reinhardt's words and the sight of the new NPX Aerial Ships... Not only bolstered the morale of the Allied forces but also strengthened the firepower of the Coalition Navy.

"Woah..." Unicorn was amazed, along with other Shipgirls.

"Oh my... They didn't cut corners this time..." Hood added, as the Aerial Battlecarrier showed no mercy against the SIRENs while Sorting More Fighter Jets.

As the whole Ironblood is becoming more and more jealous that the NPX's Ingenuity is becoming integral to German Engineering... Other Shipgirls are impressed and joyful of the Aerial Reinforcements.

Eventually, the Naval Infantry and Marine Corps started their amphibious assault, while the Shipgirls and Coalition Ships covered them.

Despite more and more SIRENs being deployed to stop the Multi-Pronged Amphibious Assault, the Joint Forces of the Coalition Navy and the Shipgirls kept 95% of the Landing Crafts unharmed.

As the Coalition Ships ran out of Anti-Ship Missiles and had to retreat to reload, the Marines and Naval Infantry landed before the Missile ran out.

Objective I completed.

Now to Objective II, and it's up to the Marines and Naval Infantry to find the SIREN Portal and destroy it, while the Joint Naval Forces buy them a limited time. At best, two hours. At worse... 30 Minutes.

"MARINES!?"

"OORAH!!!"

Countless Light Tanks, APCs, IFVs, and even Improvised Fighting Vehicles came out, as Marines and Naval Infantry charged out of the Amphibious Ship. Firing at the SIRENs on land.

Thanks to the Academy's Trans-Dimensional Stabilizer, the SIRENs lost their ability to travel in time to fight or even create the mirror seas, unlike the Early Stages.

Now they have to fight in the same game as the Solaris Humans. Sounds of Plasma, Laser, and Rail Accelerated Firearms and Vehicles' Weapons.

The SIRENs are extremely skilled in Naval Combat, not in Land Combat. Which forced many Humanoid SIRENs to go on land and fight them there. This led to the Executioner Class SIRENs getting overwhelmed, as more Elite SIRENs were forced to go upland to face the Coalition's Marines and Naval Infantry Forces.

With the Coalition Forces Advantages now at their side, many of the Pro-SIREN Cultists were about to man the Anti-Ship Weaponry, only to be mowed down by the Coalition's Marines and Naval Infantry.

With the Anti-Coastal Artilleries Neutralized from multiple positions, the Shipgirls could now get closer and provide supporting fire for the Naval Infantry and Marines.

"Move! Move! Through the Metropolis!" A Coalition Marine Lieutenant yelled. As they got into the city, and used drones along with thermal cameras to find the hidden SIREN Base.

The Azur Lane's, Crimson Axis' and Coalition's Submarines arrived to buy even more time. And then...

"Hey! Their Base is literally Underwater!!!" U-556 yelled.

"That's great, U-556." Bismarck told her.

They've found it, but now there's a problem...

"What now!? It's underwater!" Russian Marine yelled.

"If only we're brought our Specialized Submarine..." Belorussiya added.

"Great... This Operation is done for..." A Korean Marine added.

None of the Coalition Marines or Naval Infantry have fought Underwater, armed with weapons, or even have the CAV-X Bullets... The Operation is done in the eyes of many people...

Until a Danish Marine Battalion Volunteered. They managed to bring a lot of CAV-X Bullets and Combat Divers to get ready.

"Alright. This is your only chance to win this Operation." Admiral Lawson told the Danish Marines.

"Stay close with the Submarine Girls and the Coalition's Submarines. If you managed to find the Portal in there, place all the Plasma C4s you have and blow it all up. Just make sure you guys make it far enough."

The Danish Marines nodded. And so, the First Underwater Operations commenced.

With that said. The Danish jumped into the seas, and the First Modern Underwater Submarine vs Submarine Battle just commenced.

As multiple SDVs were attached to the Coalition Submarines, the Submarine Girls initiated their attack, by firing Torpedos at the SIRENs Submarines, as a distraction.

As the SDVs got close enough, the Combat Divers got out and swam towards the Third and Final Objective.

Destroy the Second Orochi and the Underwater Central Base.

Meanwhile... With the Surface Forces...

The Majority of the Coalition Marines and Naval Infantry have now requisitioned the Enemy Naval Artillery to attack the SIRENs.

"Hah! How does it feel to be shot by your own Artillery, SIRENS!?" A Coalition Marine Yelled.

As the battle on land, between the Coalition's Naval Infantry and Marines against the SIRENs and SIREN Cultists...

"..." Akagi was silent when she saw that on a Danish Marine's Camera... It's the same Orochi, that's currently inactive.

"Don't worry, Akagi." Kaga told her.

When Akagi turned to Kaga.

"This time, we'll make them pay for tricking us. Unlike before..."

She nodded.

This time, the SIRENs will pay for tricking them to make the Orochi. Along with the Sakura Empire.

"Yes... I hope they destroy it before it activates..." Akagi just hoped that the Danish Marines would succeed in destroying it before it surfaced...

Well, Akagi... If you wanted it destroyed before it gets a chance.

Ask and it will be given to you; seek and you will find; knock and the door will be opened to you.

In other words, your wish has been granted.

However, the Danish Marines have a cunning plan.

With the Central Core destroyed... The Orochi was activated. And it went up the surface.

"My god... It's happening again..." Prince of Wales muttered.

"What's going to target next...?" Bismarck added.

"You have got to be kidding me!?" Hornet.

"Not again!!!" Zuikaku added.

"What are your Marines doing!?" Kaga added, concerned about the growing situation.

And then...

[ICBM DETECTED]

"This is El-Alamein Eins. Control of the Orbital Energy Laser Strike has been approved. Target is marked." General Parker.

"Denmark's 15th Battalion here. Detonating." The Commander of the said Battalion radios.

And with a simple click...

The Orochi was blown into pieces, surprising the SIRENs that the Solaris Humans are not as simple as they believed.

"... Heh... Heheheheh... I wonder if you have more tricks up your sleeves, you Lunatic." Kaga told the Battalion Commander.

"Oh. We do... Except..."

Another Orochi came out... But...

"Fire at the Second Orochi!" Parker yelled on the Radio.

And a High Powered Laser struck down on the Second Orochi. The Same Explosion.

It looks like General Parker, Admiral Lawson, and Admiral Reinhardt have successfully predicted the Orochis, as the third one was destroyed by a Kinetic Strike.

"There it is! The Portal!!!" Lawson radioed to everyone.

"All Ships! Into it and destroy the source!"

???, ??/??/????, SIREN Singularity.

The Heart of the SIREN's Final Base to be able to claim the Solaris Earth...

But now, Admiral Lawson told to all of the ship, including the Coalition's Ships.

"We can only rely on our eyes, from here on out or we'll be stuck here by the Observer Effect. All Coalition ships, Turn your Missiles into Laser Tracking, Radar will make the Observer Effect Worse."

And the Coalition Ship obeys. Best to follow the Professional in this case. And then, they saw...

The Coalition Ships got ready to fire... Until...

"Wow, you really brought in those Coalition Guys in here, huh Lawson?"

The Coalition Naval Officers ordered to hold fire.

"I can tell, Hiryuu. Let me guess, you needed our help?" Lawson replied.

"Yeah. This time, we're going to turn this place into Ashes. Heh, it's funny that's also our Faction's name."

With that, The Final Stage of Operation Sea Champion has begun.

This time, their path to Solaris Earth will be Obliterated with a few Plasmaric Nuke.

"It looks like the Sailors and Officers of the Solaris Earth have made a final push against us." Arbiter: Temperance XIV.

"And they even brought the girls here too. Looks like they're going all in." Arbiter: The Hermit IX. "It looks like we have to go all in or the Portal to this World will be destroyed."

"I agreed. Many others have managed to retreat before a few got stranded." Arbiter: Strength VIII

"Regardless, It appears that the Solaris Earth will see the stars thanks to us. For now..." The Observer.

"Give them, one final test. And see if they're worthy to be Defenders of Solaris Earth."

And the final battle against the SIRENs has begun.

The Coalition's Naval Ships fired their Missiles at the Arbitors, now tracking them via Laser. Both El Alamein Eins and Zwei fired their Missiles, Lasers, and Rail Naval Guns. While the Shipgirls initiate battle, with the Battleships and Carriers providing Fire Support. While Crusiers and Destroyers Shipgirls advanced toward the Arbitors and Observers unleashing their Torpedos or their Main Guns.

"Argh! Not bad for their first All Out Assault." Arbiter: The Hermit IX remarked.

"Agreed. Though the Coalition Ships lacked any quick reloading capability for their Anti-Ship Missiles, it appears they're substituted by their Aerial Ships and the Kansens." Arbiter: Temperance XIV added.

"Let's continue our test with the Solaris Navy. Execute Combat Link Protocol."

"Alright! Executing IX-XIV Linked Jamming Protocol! Say your prayers, Coalition!" Arbiter: The Hermit IX.

And the Jamming Protocol has heavily affected the Coalition Naval Ships, while there was minimal effect by the Azur Lane and Crimson Axis Shipgirls. Nothing happened to both El Alameins.

"This is CVN-80 Enterprise of the US Navy! We've just lost a few of our F-35s, but we can still send Fighter Jets!"

"Suzhou reporting of the NCR (New Chinese Republic)! Our Ship can't target the enemy! Requesting Electronic Repairs!"

"JS Maya of the JMSDF! We still have sight, but our Missiles can't fire! Eletronic Repairs requested!"

"Oh dear... More work for us..." Vestal (Azur Lane) as she went to help repair the Coalition Ships' electronics.

"I wonder if that General will come back? He better be alive." Vestal META added.

60% of the 1st Task Force were disabled and had to retreat and wait for the repair ships... But...

"Hunter of the RAN (Royal Australian Navy) here. NPX's Tech managed to mitigate the effects, and we can still engage, along with RNZN Ships. Continuing Attack."

"Brandenburg of ze Deuchte Marine. Same result as ze Aussies. Continuing Attack."

But a good amount of Coalition's Corvettes, missile boats, and Torpedo Boats immediately provide fire for the disabled Warships.

With that, the Shipgirls were able to continue the assault. Along with the METAs...

Luckily, Lawson told them beforehand about the Coalition Naval Forces, before the attack...

"Jammed my Weapon Systems Again!?" Ark Royal META yelled. "Ugh... At least, the Coalition Navy managed to adapt..."

"...? Why are they using the same trick as a few years ago? Are they testing the Coalition Navy?" META Hiryuu wondered. "Damn it... I can't send my Planes..."

The Arbiters this time jammed two META's Weapon Systems... Until...

"This is Richard G. Lugar! Weapon Systems is back online! Returning to the fight!"

"Charles de Gaulle here! Our system is restored! Resuming Take off for our pilots."

"How did our Naval Systems recover quickly!? The Academy and Project didn't make those?" Reinhardt who's confused with the sudden recovery of the Coalition Navy's Systems...

"I suppose we got some reinforcements, from a friend of mine." Lawson replied to Reinhardt... While smirking.

It was Helena META. She restored the systems, which led them back to the fight.

"Well now. First the All Out assault, now her? These data are getting much more interesting. Better save it, for future use...." Arbiter: The Hermit IX.

"... This feels like the same thing as a few years ago, before we ended up here." Arbiter: Strength VIII.

"Who knows? If they become advanced and united enough, we can leave this world, and hope for the best." Arbiter: Strength VIII, and then... "Alright, Strength, the same."

"On it."

"Executing IX-XIV Linked Jamming Protocol."

With that, a good amount of Torpedo Boats and Missile Boats broke in half then it happened. Mostly the less advanced ones. Many larger Warships suffered internal damage, and the crews quickly sealed off the breached areas.

"I swear to god... They're throwing a Revenge Party for this! That's the second time, since a few years ago!" META Ark Royal muttered.

"Damn... A lot of Sailors are now on the Lifeboats... We got casualties..." META Hiryuu added, as casulties are mounting up.

"I'll be repairing with the Repair Ships, you guys?" Baltimore.

"..." META Ark Royal then turns to the El Alamain Eins & Zwei. "Hey! Buy us time!"

Which both Reinhardt and Parker nodded. And the Coalition 2nd Task Force switched roles for the 1st. The Royal Navy and Eagle Union Shipgirls also switched the Ironblood and Sakura Empire Shipgirls as to prevent losses.

The Battle Continued between the SIRENs and the Joint Azur Lane - Crimson Axis & Coalition Forces. As Missiles, Cannons, Anti Airs, Jets and Planes fight for a Battle of Total Annaliation.

While Kevin's Faction, the New Phoenix Project has focus the same stradegy as the Fabian Strategy and Combined Arms... It helped preventing the Invaders, from reaching to full strength or even half strength.

"Temperance, put some pressure of the Rear Units. Strength, swap over to linked mode, now. We can't let the Ashes recover. Others will try to distract the remaining fleet." Hermit IX told the two.

"I think their both their Admirals have saw us attempting a feint. But, doing it." Strength VIII replied.

"Initiating VIII-XIV Linked Jamming Protocol. I suppose that'll do, compared to last time." Temperance XIV added.

The Battle Continues. The already the Coalition 2nd Fleet are losing the advantage, as things are not going as planned...

"Great... Strong offense. Strong Defense. Even Gravity Well... I suppose we'll be eating shit on a shingle in the afterlife..." Parker told Lawson and Reinhardt.

"Nein, mein comrade! You forgot this?" Reinhardt told Parker...

And then the SIRENs were under attack... By both Coalition and Kansen Submarines.

"Alaska here. Engaging the SIRENs, underwater."

"Changzheng 18 of the NCR reporting. Confirmed hits."

"K-295 of Russia. Torpedo Hit."

"Ah... The Submarines... I forgot about that... Thank god." Parker sighed in relief... At least his mental capacity is still good, despite his old age.

The Battle is going well... Until...

"Oh great... They're repairing themselves again..." Essex muttered.

"I fear the same tactics will not work..." Shangri-La added... Until...

"Ahem. Ahem... All ships, this is El Alamein Eins, or General Parker speaking. I've authorized the use of WMD in this Singuality, by permission of the President of the UN. We only have ten minutes. Evacuate before it's reached to ten seconds."

They couldn't believe what they've just heard... Jacqueline is authoirizing the use of WMDs into the singuarlity.

"THAT MAD WOMAN!!! WHAT IS SHE THINKING!?" Kaga yelled.

"She has completely lost it... Everyone! Get out of here! Now!" Harbin yelled.

"Mein Gott..." Bismarck muttered...

The METAs couldn't believe that they're willing to sacrifce this battle... Just to stop the SIRENS.

Not only that, the SIRENs are also panicking...

"As the Solaris Humans gone insane!?" Observer yelled.

"We're already pushed back to our old positions... Now they're willing to do this..." Lover VI added... "I..."

"What!? You wanted to do what!?" Purifier.

"Meet the Phoenix General in person..."

"... Okay...?" Purifier was surprised that Lover VI wanted to see Kevin in person...

"We litterally put all of our mainframe in here..."

As all hope is supposed to be lost to the SIRENs...

"Request from the SIRENs." TB.

"What do they want now? More battles... More-?" Parker asked and then...

"They wish to surrender." TB interrupts.

...

First Silence...

And then... Relief...

[There should be a GIF or video here. Update the app now to see it.]

"You can call the WMDs off, dear. They've surrendered." Parker radioed to Jacqueline.

"Okay, dad..." Jacqueline replied, and ordered the Generals to stand down.

Lawson was surprised, but welcomed the peace.

After Lawson arrived to the SIRENs.

"Are you sure?"

They all nodded, which surprised the Shipgirls... And even the Coalition Sailors and Naval Officers.

But at least, the War against the SIRENs is over...

With the SIRENs order the end of their fight... The Coalition Navy also stand down. Along with the Shipgirls. While they maybe enemies, they're still created by humans, even if the Azur Lane doesn't know. But now, with the SIRENs now helping humanity to face the Leviathans. Maybe... Just maybe... The Solaris will have the chance to reach to the stars, sooner than later...

On 05/02/2034, the SIRENs have laid down their arms, and will be treated according to the Geneva Convention. 1/5 Invader Faction have Surrendered.