All of Bat's gadgets instantly f*ck up due to background magical interference.
Without Batman's magic 'prep-time' ("Gadzooks, my enemy can crush planets. I know in the ten minutes I have before he arrives I'll build a weapon capable of beating him ! Anti-Superman Spray here I come!!! ) or ......The Batkick (In such confined space the Kick's resultant reality warp would kill them all in a flurry of 'Goddamned BATMAN !'😉 he dies a painful,painful death.