Bruise tattoo

Tattoos require pain tolerance which is part of what makes them cool. But the problem is you then spend the rest of your life trying to figure out who Mona was, or translating that kanji character on your arm for people in bars. Tattoos also require piercing the skin, which gives you cooties. Could tattoos be made temporary , piercing free, but still painful?

The Phantom wears a skull ring so when he punches people, they have a bruise in the shape of a skull. Cool! But they get knocked out too, and everyone has the exact same one, which is less cool. I propose that a series of raised shapes be made so when whacked into people they will leave a shaped bruise. The whack strength could be calibrated by part of the body, either by a machine or by trained bruisesmiths who wear the bruise tattos devices as rings / brass knuckles.

Your bruise tattoo will change in color and shape as days pass, adding to its splendor. Eventually it will disappear, making room for its successor!