Recently, I've been fooling around in the latest version of the Ars Magica 2 mod, and I've make a few spells I thought might be worth sharing. I've been messing around with a project I've been calling "Procfest", because it is essentially walls proccing walls proccing walls proccing walls proccing a spell. I *might* have broken the spell system. I made a spell that, for a mere 15 mana, will, with the aid of a catalyst creature such as a sheep, scour the surface world clean with hundreds upon hundreds of lightning bolts (as in, more than one per block). Here it is:
Shape Group: Wall|Wall|Wall|Wall| //amount can be varied to accommodate computer ability; a full set of 4 will result in enough walls to crash minecraft for me.
Spell Stuff: Channel|Storm
Basically, this works because every iteration, all of the walls spawned (excepting he 4th generation walls) will spawn a wall, on every entity it intersects. all generation 4 walls will count as you channeling Storm. Due to this being exponential growth, having one wall in the shape group will result in the same as channeling it normally. Two is a bit faster. Three is a cone of white blinding death on every single mob in the area and the entire world being aflame. Four crashes minecraft. This effect scales exponentially with number of mobs, and the results given here were with one mob.
I think things like this might be why Ars Magica 2 is considered OP. Might.
I'll test this on older versions (which are more stable anyway), however, and report results.