@olcharlieboi Well, the issue is that it basically creates sentient beings which functioning bodies and are just products of one's thoughts. Sure, fatigue would limit one's capabilities along with one's inability to defend themselves, but that's something almost all quirks have. The creation quirk just makes a bunch of inorganic stuff that requires the user to have detailed information on how they function. If the user wasn't as well-versed and educated as Momo, the quirk wouldn't be all that great. Other notable limitations would be Todoroki's temperature regulation issues and Iida has to keep his exhaust pipes unobstructed to function. Mental strain is good and all, but isn't that bad when comapred to Rikidou's and Kaminari's cognitive function decline when overusing their quirks.