Unreal Edifice

Assemble {x}{r}{r}(At the beginning of your main phase, you may pay part of Unreal Edifice's assemble cost. When it it completed, Unreal Edifice is assembled).
At the beginning of your combat phase, if Unreal Edifice is assembled, you may deal damage divided up among three target creatures or players equal to the number of mana you paid to assemble Unreal Edifice.