Is there a way add a object to a family in my event sheet?

I'm making a turn based gacha game and there will be duplicate monsters, so I need a way of registering one as an enemy, I could do a boolean but that means I'll have to check every single monster in the entire game individually, I mean, I can do that, it would just save a lot of time if I could add and remove from family in my scripts.

No, you can't add objects to a family in runtime.

You need to add all monsters to Monsters family, and define "isEnemy" variable on the family. This way you will be able to easily pick friendly or enemy monsters in the game.

but like... doesn't that turn it on for the whole family... it still doesn't work if that's the case and I'd have to do it one at a time.

Not sure I understand.

You can set different values in that variable for different family members. For example, zombie may be isEnemy=yes by default. And wolf may be isEnemy=no

And you can change these values for each instance in runtime. Say, if a nearby wolf becomes angry, you set isEnemy=yes for it.