I am finding myself in need of (at least) a stack of Nether Stars... and (rather unsurprisingly) I'm disinclined to fight 64 Withers by hand. I know how to contain the Wither, and I have several ideas about auto-spawning it. About automatic killing, not so much. And there is the additional difficulty of protecting any machinery devised to kill and spawn it while it's alive. So how would I go about auto-killing a Wither? The idea I'm considering atm is to use a small room lined with diamond spikes - which (at least I hope so) aren't machines so I may be able to ward them. However, that still leaves the problem of protecting my spawning equipment from the explosions, or alternatively to teleport the Wither into the killing zone instantly after spawning it... While I'm at it, I may as well ask if there exists any machinery immune to Wither explosions.