A/N: Nah. Seriously. How do you do that? I'm terrible at relationships. Lol.

Satan knows he had screwed up.

How?

How could he had been so blind???

How could he turn away the only person whose been actually been there for him for the first years of his life?

Mammon was his Mammy.

Lucifer was the one who assigned him as his caretaker because he was too busy to even care what the young boy wanted.

When Satan was still tiny and going Rage Mode, the other brothers avoided him. But not Mammon. Even if Satan attack him, Mammon would still try to calm him down, read aloud as a way of distracting him.

That's when Mammon learned that Satan had an liking to books.

Seeing how effective because it was at getting Satan to calm down. So Mammon had started getting children's books for Satan and teaching him to read.

Once Satan got named an official Avatar of Wrath, Mammon promptly dropped a solid chunk of Grimm on books for him...much to Lucifer's dismay.

He didn't have to take care to hide such "uncharacteristic purchases" from Lucifer at that point, after all. He'd justified it to the eldest by claiming that he got to take a break from babysitting whenever Satan got absorbed in reading.

After an bit of arguing with Lucifer, Mammon somehow managed to get him to agree to waste most of the money on Satan.

And this, Mammon begin raising Satan by himself.

There were multiple attempts of murder of Satan's life by the other brothers...sometimes Lucifer as well...

Funny, how most people believed Mammon was the one whose supposed to be the Black Sheep.

But no, because Satan was more fit for that role.

When it came to Lucifer. Back then, Satan had craved for Lucifer's love, praise, and approval. But the prideful man always rejected him.

Even going over the line by saying.

"I'm Not Your Father And You're Not My Son"

Mammon had said Lucifer didn't mean it but Satan knew he did. Lucifer didn't bother to care how parental rejection affects a child.

Because of his rejection, Satan grew more angry, spiteful, & wrathful. He became unbearable.

He thought he had no one.

But that wasn't true.

He had someone.

"Don't worry, TanTan. I'll always be here for you..."

Satan felt tears poured out from his eyes remembering the nickname.

How...?

How could he had been so cruel to the person who was always there for him?

He took advantage of Mammon while teaming up with Levi & Asmo to take turns bullying him.

Even if Mammon is dumb, but he's not stupid believe he is. There is a difference.

Out of all the brothers, Satan knew Mammon was the most decent out of all of them. He even told MC this and they agreed.

He don't deserved him...

Satan: Mammon...Mammy...I'm so sorry... How do I make up for this...How do I make it up to him for all of this...?

Where could he even begin?

Then an idea struck him...

Beelzebub ran away to the Human Realm to look for Mammon. So why don't Satan do the same thing.

It's obvious no one here is going to miss him.

Well...Except maybe Solomon and Asmodeus.

All because he couldn't control his anger... It's not his fault. He's the literal Avatar Of Wrath. Even if he tries his best to remain calm. There will always be a time where he will snap. Especially if you mistakenly push his buttons.

So if he give Lucifer want he wanted. The Unwelcome Child born from his wrath to leave so he won't have to deal with him anymore.

Satan: But the question is...How do I find Mammon...? There has to be a easy way to look for him.

Wait...Maybe there is...

Now that remembered, Lucifer once gave Mammon a cursed shiny bracelet that worked like tracking device. If he used his one of his curse books. He could be able to pinpoint the location of that braclet.

Working his magic, Satan used a spell and manages to locate him in record time, thanks to that bracelet.

*Later*

Satan shouldn't be all that surprised that Mammon was in Japan. If he's there, then there's a possible chance Beelzebub is too.

Using the spell, he found the small apartment close by and soon find himself at the doorstep.

Satan: (I can't believe it. I'm actually here...I'm going to see Mammon in such a long time...)

It's been months since any of them last saw him. He was scared. He knew if he knocks on this door and Mammon opens it up.

There's a high chance he might slam the door on his face or ask him to leave.

Mammon did made it perfectly clear he wanted nothing to do with them. But if Beel is here too and is given a second chance, then Satan wants another chance too.

He won't let this chance go to waste.

He find whatever he can to make it up to his Mammy.

Just before he knocked on the door, he heard voices inside.

It was Mammon, his daughter, & Beelzebub.

Mammon: Dang it Beel! Did ya eat the leftover custards again?

Despite the accusation, he didn't sound all that angry. Also, it seems like Beel is here too. Much to Satan's relief. He's glad his younger brother isn't somewhere lost & looking for food.

Beel: Sorry Mammon...I'll buy some more.

Mammon: Ya better! While you're at it! You could go out with Kanon & buy some ice cream!

Kanon, the name of Mammon's daughter. Satan still couldn't believe his older brother slash caretaker had another child.

Didn't matter if she was adopted, Satan felt an tinge of jealousy and rage. He felt replaced.

Kanon: Yeah! Let's get our favorite favors, Uncle Beel!

Beel: Of course, Kanon. I'll get you the bestest ice cream at Madam's Screams. You'll love them.

Kanon: Ohhh~! I can't wait!

Satan wondered if humans could even eat food at Devildom? Well then again, MC could & Solomon...well that guy should try his own cooking every once in a while and see how that feels!!! Honestly, Satan could never understand his best friend. Solomon himself was a huge mystery.

Because seriously, Solomon! Go over a recipe & stop poisoning people!

Mammon: I'm glad ya to see ya too are getting along.

Kanon: Yeah! Uncle Beel is the best! He has a big appetite and he's really sweet too!

Beel: *Munch* *Munch* I'm glad to hear that. Thank you Kanon. I'm happy to get to know you too.

Mammon: Oi! Beel! Quit eating my eclairs!

Beel: Hmmm... They're really good. *Munch* *Munch* *Munch*

Mammon: Are ya even listening?!

Satan: (So it seems Mammon & Beel are able to bury the hatchet between them. So how could I...?)

At this moment, another idea struck him...

Satan:....Oh...I can't believe I'm doing this. Luckily I brought this just in case...

.

.

.

.

.

*Ding Dong*

Mammon: I'll get it, Kanon!

Mammon went over to the door & once he opened it up. His eyes went wide upon seeing Satan.

Mammon:.....Satan?

The fourth eldest was at his door and he had a book covering his face. Mammon was not sure why but he wasn't in the mood. While he was okay with Beel and was able to recoil their relationship. He's not even sure if he wants to see the rest of the other brothers.

Satan:.....

Mammon:....What are ya doing here? What d'ya want?

Satan:.....

Mammon was getting impatient. Is Satan ignoring him on purpose? The nerve of him! The fourth eldest may be smart but he sure don't got no manners. An trait the brothers failed to teach him...

Mammon: Satan. I'm not sure what yer doing here or how ya got here but I don't care. If you here to insult me...ya can leave.

Satan:.....

He's the one who showed up at Mammon's doorstep for a reason and he still has to gall to ignore him! Who does he think he is?!!

Mammon: Satan...? Wait...what are you reading.

Mammon read the title of the book and his went wide.

"The Forbidden Book Of Toddlerization"

Mammon: Satan...Don't tell me you...

Satan: *Child* Hahahahaha~! Mammy! Hahahaha~!

Satan finally looked up and was laughing like an innocent child.

Mammon: Not again, Satan...(This is the third or fourth time this happend...Lucifer told him not to read that book.)

Satan: Do you want to play hide n seek? Hahahaha!

Mammon: Well...Maybe one round won't be bad...

One brother popping up after the next...

Just what had Mammon got himself into???