If u use a sparrow and crash into them it causes slight damage and if u get close to them they have explosive weapon and can weaken themselves with every hit u take. It took me and my friend about a half hour but we killed to acolytes. The hallow knight can't be killed this way unless many people attack a lot because he can regen. Anyway try if u want to be able to say I killed a invincible enemy in the beta without knocking him off

Nice