Melter

Melter have one extremely obvious target – the Spherical Guardian that appears in acts two and three. It is a one stop solution for destroying this enemy, similar to the silent’s use of poison. For this reason I usually only take one copy and get it during act 2 if possible. it is surprisingly easy to get value out of discard in other encounters as well, as a large amount of enemies do block. What's more, Melter actually does decent damage for 1 energy.