You can use a sword or a metal weapon to resolve it, but that's too obvious and easy to blame.
Why not go to the cartoon city or the place where games are sold and use the paintings of martial arts games? Cold weapon stickers, preferably white swords, other backgrounds are yellow, not red. Stick it on your glass door, it looks good and won't cause conflicts, killing two birds with one stone. Anything similar to the picture below will do.