Prismancer

Craft at a mythril/orichalcum anvil from Hallow produce plus Twins souls: 10 Crystal Shards, 2 Unicorn Horns, 10 Pixie Dust, 8 Souls of Light and 15 Souls of Sight. So: an underground Hallow farming trip, then beat the Twins (Ophthalmologist), then assemble. A lovely controllable-projectile weapon for its tier, too.