I see that powers for the most part are retained so long as they are not game breaking, which is a little broad so I wanted to ask something to clarify!

Emet has creation magic, which means he can create essentially anything he can imagine and has the power to do, and canonically he is an unending well of aether (magic power), and was able to recreate an entire giant city that barely taxed him. So, that power is a bit extreme, and would otherwise make the regains moot, so I was wondering what would be the call on his creation magic? I would like if he could keep it to some degree for shenanigans, but I also don't want it to be game breaking (even if he wouldn't likely recreate Amaurot again).