"...some high-leverage way to be evil which he could accomplish from prison as extortion, or...?"
...They probably have no strong opinion about me and some reason for general caution and occasionally even when I am not in your company I value my privacy.
"Suppose that makes sense. I am curious but just sort of dispositionally, I'm not sure what I'd actually say to him."
"Yeah, where does one go for a conversation opener there. 'So, I hear you used to be evil, what was up with that, can I adapt your heartwarming redemption story for my world's prison system'?"
"Yeah. What kinda magic can he still do while in troublemaking-restricted lockdown?"
"Yeah, I'm sort of wondering if the other Valar are going to have a response on that one before I'm like forty... 'creating energy'?"
"Our world's working definition of magic is things that create physical material from nothing, change physical material in ways it wouldn't usually change without being heated a lot, or directly creating heat, light, sound, etcetera. Those are the things that are magic; they're all hard to do lastingly. The Valar can do them mostly at will. You should ask my father if you want an explanation more sophisticated than that."
"They're not hard for servantmakers to do lastingly. Well, some of them, I can't create physical material from nothing."