you need to get a subspace tripmine and imbue it with fire, ice, and electricity. if you or any other people don't have the achievement from getting a countercast (too lazy to type how to get it, watch a tutorial for it i guess), you can only do this in stage 4 from the wizards. but with the accessory from the achievement, you can do this in earlier stages.
how do u do calamity?
you need to get a subspace tripmine and imbue it with fire, ice, and electricity. if you or any other people don't have the achievement from getting a countercast (too lazy to type how to get it, watch a tutorial for it i guess), you can only do this in stage 4 from the wizards. but with the accessory from the achievement, you can do this in earlier stages.