What player can cause cancer in their enemies (plus points for one of a blood aspect because karkat lol)

I could see a Space Player using radiation, Light as well like, the UV rays from the Sun. Curiously enough, though? My first idea was a Maid or Sylph of Life- Cancer is faulty replication of cells that start to just sort of take over, so. ‘Improving’ Life would likely have this effect, wouldn’t it?