@reader__writer__ well I've been developing a quirk for a while and I wouldn't be against you using it if you like it
It was made as a quirk for an oc I made named akio who then later became my current OC Kirk wantanabe
He carries multiple EXTREMELY heavy (yet small) blades on him and he can use them because his quirk is metal work.
Synopsis:
Metal work is a emitter/transformative quirk that allows the user to control metallic as a whole copper, iron, mercury, most metal in general, but since the quirk controls metal it can be used to weld without heat, liquidate any metal, and take metal from blood.
The transformative side of this quirk is within the blood, the ability gives the wielder 50 times the normal amount of iron in their body giving the power to harden skin to iron and create retractable blades from blood.
Weaknesses
If over used the user will get light headed
user is magnetic
Swimming is possible but is more difficult
Under rain user is more likely to be struck by lightning (warning don't get close to denki or midoriya when their quirk is in use)