One can only defeat so many villains that want to "cover the world in darkness" before one starts to look for a different flavor of horrible.
EVIL JUST GOT EMO!
The idea of using tattoos to contain magic powers is not a new one. The Ink gauntlet follows the basic premise of using rare and precious inks to inscribe spells into the skin of a mage or would be spell-imbued person. Some of these inked spells might be permanent, while others might fade after being used once, or a preset number of times.