OK, this build is intended to be just a little blasty fun, and not something at all powerful. This is why I'm not taking any of the really good options.
Human Warmage 1/Warlock 4/Eldritch Theurge 10/X 5
Why is this, in any way, shape or form, fun?
1. Fire AoEs through your eldritch blasts.
2. 3+Cha times per day, apply eldritch essences to your spells.
3. Put touch spells onto your Eldritch blast.
Now, you also have to notice that you can do stuff like combining 1 or 3 with 2, so as to do stuff like throwing Fireball onto a Scorching Ray.
Or onto a Heightened magic missile.
And then there's stuff like throwing Brimstone Blast onto a magic missile, giving you a handy little fire starter. Or making Vitriolic Magic Missiles; no save, no SR, acid damage. Have fun.
Throw earth spell, snowcasting and flash frost shenanigans on here to make evocation something to be (very mildly) be feared!
Any suggestions for the last 5 levels?