I managed to build a set with 8 MP, 508% earth damage, 7 AP, 255% water damage, 41% heal, and 21% crit. It is designed for level 140 at the moment.
Your spells would be Fertilizer, Manifold Bramble, Mudoll, and Drain. The most important, though, would be Earthquake. At level 140, earthquake hits 55 for 1 mp. You can use it five times a turn (as the condition states) and still have three for moving yourself around. At 508% damage, assuming no earth resist and no crits, you would hit 279 damage, five times a turn. 1395 damage before you spend and AP. Then move on to either manifold or fertilizer. Another 492 damage, for a whopping total of 2000+ damage, to everything in an AoE.
I know its obviously not the BEST build. But, it isnt a bad build. Plus, its lulzy and you'd be a special snowflake.