Mage:
Magery
Eval
Med
Resist
Necro
Spirit
Poisoning
Use a mage weapon. Evil omen/ poison does level 5 if you are within 2 tiles
Dexer
Wep Skill
Tact
Anat
Heal
Bushido
parry
Poisoning
The sum of your magery and posoning needs to equal 200 (so 120 mage 80 poison). For a dexer just take it to 80.
While everyone does carry cure pots, sometimes they fail vs level 5, and they also disrupt cross heals, so they aren't worthless.