I did some cost/damage effectiveness research for maxed out powers. All were tested with a beginner wizard (using cheated tomes to buy the powers):
- Burning Hands: Too damn much MW, pathetic damage.
- Magic Missile: 7 MW, 5 missiles, about 17 damage each. Missiles home in.
- Cloudkill: 16 MW, small radius, about 21 damage per second. Don't know how long. Takes time to work.
- Fireball: 10 MW, big blast, about 85 damage. Flies off harmlessly if you miss.
- Vampiric Drain: 27 MW, small radius, about 16 damage per second, 8 extra damage on the initial blast. Lasts for a few seconds. Feeds a good percentage of the damage back to you. Works the other way around on undead.
- Circle of Cold: 35 MW, big radius, about 60 damage. Low chance of freezing.
- Icy Sphere: 50 MW, small radius travelling with it, deals about 7 hits to a stationary target (less if they move away, more if they travel in the same direction) for about 11 damage per hit. Low chance of freezing.
- Meteor Swarm: 55 MW, calls down 12 meteors spread over a big area, each explodes with a big radius, about 42 impact + 25 fire damage each. There's a little delay before the "air strike" hits.
Conclusion: Fireball is clearly most cost effective with huge damage to lots of critters for only 10 MW. Meteor Swarm is slightly less cost effective, but deals more damage in a shorter time than a series of fireballs.
Don't know much about the non-damage spells...
- Gust of Wind: Lots of MW, might have some very limited uses in self-defence. Slows critters for a few seconds besides pushing them back.
- Globe of Invulnerability: Haven't really tried it.
- Sleep: 21 MW, lasts for only a few seconds. Slow to cast, has a serious delay before it can be recast.
Then there's the finishers:
- Jumpkick Finisher: 9 MW, only hits critters to your front, about 35 damage for a starting wizard.
- Staff Spin Finisher: 15 MW, hits critters on all sides, about 64 damage for a starting wizard.
Finishers can only be used every so many hits and you can save them up for only a short time, but you can score critical hits with them. I suppose damage increases when you become stronger, more specialized or get a better weapon, but they really seem a waste of MW compared to the fireball.