however, with sunfire, you only need to know approximately where they are...
spell trigger sunfire, sunfire, sunfire
spell sequencer mirror image, stoneskin, teleportation field...
(the sequencer is if the chavalier is immune to fire)
the sunfire has a good chance of blasting the chavalier...
if the chavalier is smart and is immune to fire, start summoning skeleton warriors...they can see invisible, and if the chavalier starts turning undead, use true sight while he is busy turning undead...then use project image, and start summoning both mordenkainen swords and skeleton warriors...if he quaffs a potion, the skeleton warrior will target him for the mordenkainen swords, if he turns undead, the swords will disrupt him...and he doesn't have deathspell...