Chronic Logic

What kind of builds do you use against the AI (aside from the hydra)? Which seem to work the best?
I've played against the AI for the last 10 levels (at 58) with 5 rangers which has proved quite effective except when there are 3 or 4 heretics. (Or when the AI starts spamming heavies.)

If you read the description of the Magus' spirit form (inside a game) it says the spirit is only supposed to last two turns.
I can't be more specific right now since the AI hasn't used one against me today.