[Soyweiser]

Make his supporting army run away, taking away the surrounding provinces.

Also, 22 MR is rather low. If he doesn't have 100FR, blindness spam. With boosters and in a communion. (so you get even more penetration).

Just casting soul slay with a boosted pretender might be enough. (give the pretender some penetration boosters, and he will go down quickly). Rune smasher, ring of wiz/sorc, + spell focus, is already +4. Add a 16 slave communion for even more + astral and thus penetration. The 2 astral boosting spells. Assume base Astral 6.

That would give +4 penetration from items, +1 from the base level, +2 from the communion, +1 from the boosting spells. For a total of +8. Total roll he must resist 20 (base mr check is 12). Which gives a 30% chance of each soul slay spell killing him outright.

Just pilling on the horror marks might also work. And why is that dude not cursed yet? There is a D1 spell that does that.

Life for a life spam might also work. Iirc it does 40 AN unresistable damage.

Also, get some quickend thugs to dualwield the axe of hate. With a lot of attack boosters. If hit, an axe of hate does 50 fatigue damage iirc. So he will be unconcious in seconds. (Of course, the aegis is a problem, you need both high attack skill and high mr, expect to lose all thugs and this not to work. An Axe of hate, burning pearl, quickness and a ring of the warrior should give +16 attack. Summon some sleepers with starshine skullcaps and rainbow armors for a attack 31 mr 20 commander).

You could also try the spell that causes him to be attack by the souls of everybody he killed. Just cast it with a boosted caster. Forgot the name atm.