What builds are you using to beat the ____mancer challenges? (RW3)

I am enjoying RW3, and particularly with the removal of consumables, am finding it a lot more challenging than RW2.

I am, however, finding some of the single tag challenges quite difficult. I don't love that you are limited in equipment as well as spells, as it leaves you at the mercy of RNG to get the right components.

I have currently beaten:

Cryomancer (Hailstorm Blizzard, Prismatic Beam and Ice Word + Chill Wind made short work of this)

Manamancer (Magic Missle with Disperse and Cantrip Cascade + Ion Tentacles)

Pyromancer (Rain of Fire most of the work)

Electromancer (Chain Fireball + Watcher Form)

I have been trying out the Holy, Dark, and Metal challenges but am finding them quite difficult. I'm curious, for those who have beaten them, what builds are you using to beat these challenges (any and all, regardless whether or not I've mentioned them above)?