Ace doesn’t act out of malice, he just takes makes sure that certain people can never get away with whatever they did ever again.

And we already know he can take permanent measures.  Well, we know of ONE time, anyway.

 

↓ Transcript
Aoi
It’s very important that you not discuss Ueada-sensei’s actual motives with anyone. As long as this isn’t common knowledge, my father and the organization won’t have to take any permanent action. Right now, all my father will repeat over the phone is, “It’s taken care of.”

Dr Lane
Ah. So, Ace has taken a hand. Knowing him, it’s likely Dr Ueada and your step-mother have been allowed to run. And anytime they settle down, they’re going to be made aware that they haven’t successfully hidden. They’re going to spend the rest of their lives looking over their shoulders.

Aoi
You think so?

Dr Lane
If they’re lucky.

Ace considers prison time being let off easy.

There’s a former school coach, now a registered sex offender, that isn’t able to find any work more demanding than waiting tables.

Aoi
Remind me to never really piss Ace off.

Dr Lane
That’s easy. Don’t hurt anyone he cares about.