I defeated Kangaxx in three times, although I didn't die from imprisonment and I didn't use the tactics on the board. First time around, he got me by surprise (sort of) and the meteor swarms killed three of my characters, one of which permanently. Second time he imprisoned Minsc but I didn't want to walk back through all the auto-saves to get a freedom scroll at the Adventure's Mart. Third time around, Kangaxx was toast
(BTW, I didn't even use summon spells, maybe I was just lucky with my dice rolls
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The last arrow of Legolas kindled in the air as it flew,
and plunged burning into the heart of a great wolf-chieftain.
All the others fled. -J.R.R. Tolkien, The Lord of the Rings