Question/Suggestion(?)

[SilveroGhost]

Hello! I first want to say this mod is fantastic, this is something I've been searching for over the past few months and it is absolutely wonderful especially since its up to date. But I do have a question. My friends and I are aiming to make sort of like our own RPG/DND game in Minecraft and some players characters are of hostile mobs, I was wondering if there's a way to make it so a hostile mob wont target one player but will target everyone else.
For example a player is a phantom and I want them to be able to stand in a flock of phantoms and be ignored while the other players are attacked without having to prompt them in anyway aside from existing within the target range.
Would there be a way to implement like some sort of blacklist or whitelist of individual players IGNs or user ID'S so I could individually add or remove hostile mobs that would attack each of them? Or if there's already a way to do that, how would I do so?
Regardless thanks for reading my ramble and thank you for all the work you've already done on this mod :)