10. Tanjiro Kamado VS Jonatha Joestar (Demon Slayer VS JoJo's Bizarre Adventure)

Connection: Both are kind-hearted fighters who slay the undead with abilities related to the sun (Water Breathing and Hamon). Both wanted to save their kin (Nezuko and Dio Brando) from their undead status and bore a mark relating to their bloodline.

Who wins IMO: Jonathan probably. Tanjiro may be more skilled than Jonathan, but Jonathan can react to lightspeed compared to Tanjiro's lightning. Plus his Hamon can directly affect his organs which Tanjiro uses his Water Breathing abilities from and heal Jonathan on the fly while only needing a single breath to recharge.

9. King K. Rool VS Blackbeard

Connections: Both are overweight, greedy pirate kings who led a pirate crew and are the main nemesis for the protagonists of their series (Donkey Kong and Monkey D. Luffy). 

Who wins IMO: There have been people scaling Rool to Mario and the main cast but it's a shaky scaling and Blackbeard has FTL scaling over King K Rool's and even using DK's moon feat, both have Gigaton strength and Country level feats. Unless the Mario scaling is proven to be true, Imma go with Blackbeard for now.

8. Akame VS Killua Zoldyck (Akame Ga Kill! VS Hunter x Hunter)

Both are assassins created at a young age who have siblings from a bloodline of killing. Both also have a form that increase their speed (Godspeed and Ennoodzuno)

Who wins IMO: Akame. Unlike Killua she can dodge and react to lightning and Murasame is a curse not a poison so it could affect Killua.

7. Nero VS Hellboy (Devil May Cry vs Image Comics)

Connections: Both are human-demon hybrids who possess an arm that could destroy the world (Devil Bringer and Right Hand of Doom). Both use swords and guns and have a transformation from using their demon-half (Devil Trigger and Anung Un Rama)

Who wins IMO: Hellboy. Universe DMC got debunked since Mundus apparently created a universe through hax, not strength (http://g1dbteamblogs.blogspot.com/2021/07/death-battle-predictions-hellboy-vs-nero.html for evidence). Hellboy is more skilled and experience than Nero and is also immortal, so even if Nero outstats him he can't deal with that.

6. Bill Cipher VS Discord (Gravity Falls VS My Little Pony)

Connections: Both are reality warping deities who are the main nemesis for the heroes and are known into tricking anyone.

Who wins IMO: Discord. He feeds off chaos and Bill using Weirdmaggedon fields his magic, which Bill is weak against. And no, I don't believe in 12D Bill cause that's sheer outlier right there.

5. Ladybug VS Randy Cunningham (Nickelodeon VS Disney)

Connections: Two black and red themed heroes who are highschool teenagers that only their friends know and who's powers come from an item (Miraculous and Ninja Mask). They fight villains who use negative emotions to turn people evil and protect an item (Miraculous Spellbook and NinjaNomicon)

Who wins IMO: Ladybug has more powers but has a time limit which Randy's Ninja Mask does not. Plus he has more skills and taken down more stragetic fighters before.

4. Rayquaza vs Bahamut (Pokemon VS Final Fantasy)

Connections: Both are draconic deities who only lend their power to summon worthy or have defeated them in a fight. Both have very powerful beam attacks (Hyper Beam and Megaflare)

Who wins IMO: This is tricky because Bahamut has different incarnations ranging from Bahamut Fury to Bahamut SIN to Primal Bahamut. One Bahamut has universe levels of power which trumps Rayquaza's Solar System level. It's only fair to slightly composite Bahamut the same way the did Leonardo. But other than that, I think Rayquaza has this.

3. Frieza VS Megatron (Dragon Ball VS Megatron)

Connections: Both are purple and white theme galactic tyrants who conquer/destroy planets, lead an army (Frieza Army and Decepticons) and the the main rivals to the heroes who defend Earth (Son Goku and Optimus Prime). Both also have final forms (Golden Frieza and Galvatron) and beam attacks they spam (Death Beam and Fusion Cannon)

Who wins IMO: Frieza. Based on Dragon Ball's larger universe, he held the strength and destructive capability advantage. But those who say Frieza stomps easily (CoughDBZtardsCough) only knows the cartoons and not the IDW Comics. Megatron has years of combat experience over Frieza, far more skilled and his antimatter can do serious harm to Frieza since it's fatal to organic beings. While Frieza would come out on top, Megatron would put up a serious fight.

2. Vilgax VS Ridley (Cartoon Network VS Nintendo)

Connections: Both are space tyrants who lead a technologically advanced army, seeking to conquer the universe with a device (Omnitrix and Metroids) that is worn by their main rival (Ben Tennyson and Samus Aran). Both have survived near-death experience and received cybernetic implants which made them stronger. Both also possess numerous powers and forms that were gained lost over the years.

Who wins IMO: Vilgax but by a slight margin. Ridley held the upper hand in strength and durability thanks to his healing factor which regenerates from the bone. He can also fly and is smarter than one thinks. But Vilgax has the speed advantage, far more skilled and has years of combat experience over Ridley. Though Ridley is called the Cunning God of Death, Vilgax has outsmarted the demon god Diagon. Also Ridley becomes bloodlusted in a prolonged fight which Vilgax would exploit. Not to mention Ridley's healing factor takes time and only speeds up by consuming human flesh, and Vilgax is a Chimera Sui Generis which is alien. But the biggest advantage Vilgax has possible the Malware Armor. It's a debatable whether you wanna include the armor, but should DEATH BATTLE give Vilgax that, Malgax curbstomps anything Ridley throws at him: Laser weapons could deal with Ridley's Plasma Breath, jetpack can match his flight and the Tachyon Cannon is the perfect counter for Ridley's healing factor since it destroys at the sub-cellular level and his regeneration is described to be cellular.

Fuck Ridley VS Rayquaza and Megatron VS Vilgax.

1. Kim Possible VS Samantha Simpson (Kim Possible VS Totally Spies!)

Connection: Redhead highschool teenagers who lived a double life as spies along with their friends after an incident. they also are the leaders of their team and the most serious of the group (Team Possible and Totally Spies), despite easily being smitten by boys.

Who wins IMO: Kim Possible. Sam definitely has the strength advantage since she fought robots bigger than the ones Kim has faced and has the more deadlier gadgets. But Kim has fought multiple people at once and dueled Shego, her equal with the exception that she has superpowers, many times and won. Both dodged lasers, but Kim does so repeatedly and in different directions. She also had superior hand-to-hand combat skills over Sam.