He is located at the end of the ice/water ( what ever you call it on your server) tower . you can actually run all the way up to his level and kill him. level 70 + mobs will just reset and forget about you. if you are level 65 like my ranger was :P they will follow you up and run you down. But 70 plus ... no worries . just run the levels until you get to his. kill all adds and burn the fabled.
My warrior and shaman level 80 has killed him enough to have his weapons on all my alts and my guildies also and a few friends :P hahah same goes for all the fabled in BOT .well not Agnar.. don't like spending hours on one guy hahahah
Long story short. He hits around 1600 to 2000 has a mana drain spell ( i forget the name ) not a problem for a shaman ...when it lands :P fight normally takes a few minutes. just kill him where he stands with your back to the wall. he has a few AOE also , killed the shaman's pet a few times...i wish those where more solid :(
With cold resist up, nothing much lands.
Good luck and enjoy the fight and loot :P