[UserUnfriendly]

chain contingency ignores acuity, and so you can cast in middle of combat, and it will instantly trigger next round.

when you're next to the lich,

cast on SELF, when you see enemy

sunfire
delayed blast fireball
delayed blast fireball

will usually fry them. (don't worry, casting sunfire will make you immune to fire for a round. and even though liches are immune to sunfire, they are not immune to delay blast fireball)

try casting insect swarm or creeping doom on minsc or valygar, and have him run ahead. get him close enough, and he will infect enemies.

planetars are immune to deathspell.