LonePaladin
Explorer
You're flinging 9th-level spells and worry about the punch? What's wrong with implosion? Energy drain? Go the lazy route; spend some XP and cash and gate in something really nasty — if you stick with a single creature, it can have up to twice your caster level in Hit Dice. Think pit fiends. Summon monster IX has some really vicious critters available, especially to evil casters. And you can always blast an area with a storm of vengeance.