Since coming back from his stay in the celestial realm Satan grew even more depressed and angry
And begin to lash out a lot. especially with Diavolo which would only turn into arguments where most Barbatos had to intervene to try and calm the situation down.

Diavolo tried his best to help Satan to make him happy and understand but he never could. All he wanted was for Satan to understand and that he wasn't a bad demon.

He. Wanted desperately for Satan to be happy with things but no matter what Satan never was and his hate towards Diavolo only grew.

And Diavolo grew impatient and was getting frustrated that he couldn't make Satan understand.

Yes Satan wasn't attempting to leave wasn't saying a word to anyone.

But Satan was causing so many problems behind close doors.

He was constantly avoiding Diavolo and when he couldn't would fight with him nonstop and attempt to ruin his day. With work and relaxing.

He was making Diavolo's life a living hell doing everything he could to make Diavolo just as miserable as him.

But despite everything Diavolo never escalated the situation or did anything to make Satan hate him more. He just let Satan do as he wanted. But he was Reaching his limts even though Satan had every right to be mad.

Anyway today right now Satan and Diavolo were agurging again about how his complaining and tantrums were causing problems.

And Diavolo tried to remain calm as Satan was just yelling at him going over once again about how horrible he was. and how much he was suffering because of him.

Diavolo : Satan please just calm d-

Satan : WHY THE HELL SHOULD I!? YOU ONLY WANT ME TO SHUT UP BECAUSE YOU CAN'T FACE THE TRUTH! AND THE CONSEQUENCES OF YOUR ACTIONS!"

Diavolo : when will you understand that I had to do this!"

Satan : NEVER! BECAUSE THERE'S NO REASON THAT COULD JUSTIFY THIS!"

Diavolo : Satan please just stop! This will solve nothing!"

But yet the aguring continued and Diavolo was becoming tired of this daily routine they were in. It was exhausting and pointless.

Anyway he suddenly snap and grabbed Satan's wrists and yelled as Satan struggled to get away.

Diavolo : WHY CAN'T YOU JUST UNDERSTAND! IF YOU JUST UNDERSTAND EVERYTHING WOULD BE FINE!"

Satan : Let go! Your hurting me!"

Diavolo : YOUR JUST MAKING THIS HARD ON YOURSELF! I'M DOING THIS FOR YOUR OWN GOOD! FOR EVERYONE! BUT YOU REFUSE TO SEE THE BIGGER PICTURE!"

Satan : I said let go!"

Diavolo : NOT TILL YOU LI-!?

Suddenly he got a glimpse of them in the mirror and saw how scary and angry he looked.
And saw what he was doing to Satan.

And then looked at Satan and saw that look of fear in his eyes and pain.

And he immediately let go and said shock and horrified in himself. And seeing the marks he left on Satan.

Diavolo : I.... I'm sorry....i-

Satan then immediately ran off to his room.

Later in the night time Diavolo was worried about Satan and hadn't talked to him since what happened earlier and as he knocked on Satan's bedroom door he ask.

Diavolo : Satan..... can you please open the door......"

Diavolo didn't get an answer but did hear the door lock so he just sat down against the bedroom door and said

Diavolo :. I....I just....I don't want to cause you any harm but that's all I seem to do to you.....

I know this is wrong....I know what I did was. Wrong....I hurt you....I keep making up you scared of me..."

Diavolo was only met with more silence but then after awhile he spoke.

Satan : .....your desperate for me to understand this. Most likely to convince yourself that what your doing isn't that wrong"

Diavolo : ..... honestly your probably right....."

Satan :......I'm not willing to understand because there is nothing to understand.

But you did this because it was the only way to keep your father away?"

Diavolo : yes"

Satan : why me? Why did it have to be me?"

Diavolo : .....it wasn't all just random. A lot went into looking for someone who would be fit and perfect.

It's hard to explain but it was always you that came up"

Satan : ........what makes you think I won't just cause the fall of Devildom out of spite......"

Diavolo : you won't do that."

Satan: it's tempting though"

Diavolo : ...... goodnight Satan....."