That's a lot of HP...
Lightning Bolt is actually useful through most all of the Gold Box games (it also really blows when Blue Dragons, Storm Giants, Black Mages, or Blue Meanies aim them effectively, banking them off walls to hit your mage twice).
One of these days I'll actually figure out how spells like Cone of Cold and Meteor Swarm actually work, but my aiming skills sufficed for now.
This is one of the few Gold Box boss fights in which the player has the ability to prepare against the encounter's most dangerous moves. Resist Fire, Fire Shield, and Mirror Image all protet against the Fireballs and Red Dragon breath weapons that are thrown around, meaning that failure to gain initiative doesn't result in the makings of a total party wipe. Yeah, a few spell casting were interrupted, but my characters were only taking about 33 damage from each breath attack as opposed to something ludicrous like 60 or over one hundred without spell protections.
One lieutenant down, three to go. Although I haven't the foggiest why Bane,
the Lawful Evil deity of the Realms, would have a bunch of Chaotic Evil tanar'ri as his closest servants. Are the Baatezu on strike? Did the tanar'ri decided to really chap their (im)mortal enemies' asses by working as scabs?