Kay so uh spoilers obviously
We don't actually know Worrick's real motivations. What we know is:
1) Worrick was hated by his family as a child, as he was born from his father's mistress. Then, he met Nicolas and had his first "friend" ever. "Friend" because Nic is a Twilight, and he was trained to obey the Normals, so I think Worrick was never sure whether Nic stayed by choice or by duty.
2) We know that at some point riots ocurred and that Worrick's family's mansion was attacked. Around that time, Worrick's father (who was beating him when he was drunk, so quite often) had badly injured his son. We're shown a flashback of an injured Worrick talking with Nic, saying that his father will probably kill him next time, and Nic signs "kill". In a later flashback, we see that all of Worrick's family is dead, except that instead of a rioter it's Nic that's killing the wife and son of Worrick's father. We can suppose he's killed the father too, as when rioters invaded the mansion the father was beating Worrick again, injuring his eye in the process.
3) In that same flashback, we see Nic attempting to gouge out Worrick's injured eye. I think he says something like "that's not necessary anymore". Then we also see Nic trying to kill himself (his mercenary father had abandoned him some time before -> big abandonment issues for both Worrick and Nic), only to be interrupted by Worrick. If I remember well, Worrick says/thinks something along the lines of "I won't let you die after all you've done". It's right after this event that they arrived in Ergastulum.
4) Worrick has always had a superior memory, he can remember anything he sees. That made him earn the name of "Storage". Because of this skill, no mafia clan would hire him (except one).
5) To sum it up, Worrick has a lot of grudges to settle, against a lot of people, who happen to all live in Ergastulum. He still has perfect memories of all those he's lost (see in the recent chapters, he did not take Connie's death well), and of all those who've hurt him (same, recent chapters, a lot of clients and client's relatives at Big Momma's have tried to hurt him, and add Nic to the mix), and the one Mafia Godfather who accepted to let him work for him, gave him a chance, was a bastard all along - Worrick is imo fed up with all that.
I think he wants to go out with a bang and take as many people as he can with him.
Thank you sm!
I don't get why he would see Nicolas as his enemy tho. Maybe the guilt? Bc Nic didn't kill Worrick's family out of his own motivation. He probably did it bc he understood that's what Worrick wanted or to save him. Ugh. I don't want the guys to fight each other =_= and I don't like when a character goes all out on his revenge without caring for those who do care for him, like Nico, Alex and the little girl's mafia family...tho I guess that's one of the issues in this story. They are all pretty much willing to do anything to get what they want/need ;;

Can someone explain what's going on with Worrick? what is he trying to do? destroy the mafia from the inside? what are his motivations? I'm so confused lol If anyone is willing to do a little summary on Worrick for me, I would really appreaciate it bc I can't seem to understand what he is planning, and I don't think going back in the manga is gonna help me. My reading comprehension is all messed up rn. Also, why do they call Worrick Storage? D: Geez =_= I'm sorry if I'm annoying lol