The Summoner is a quest boss and players are required to kill him in the fifth and self-titled quest in order to be granted access to the Canyon of the Magi. In Hell difficulty on battle.net he will drop the Key of Hate, a requirement to access the Pandemonium Event.
The first part to defeating The Summoner is actually finding him. He will always be located at the end of one of the four branches of the Arcane Sanctuary. If the player picks the wrong direction there will be a dead end with several chests, otherwise the quest cue will pop up indicating The Summoner is near. He will be able to attack the player before getting into visible range with deadly cold spells, so one should be sure to clear a path up to his platform before charging in. Fortunately he does not have much hp.
||Difficulty||Health||Resistances||Drain Effectiveness||Locations (Monster Level)||Preset Attributes||Highest Rune Drop|
||Normal||82 - 110||75||30||30||30||30||30||100%||Arcane Sanctuary (18)||Extra Strong
|Nightmare||1,290 - 1,642||75||30||30||30||30||30||75%||Arcane Sanctuary (51)||Ko (18)|
|Hell||6,167 - 7,849||75||30||30||30||30||30||50%||Arcane Sanctuary (82)||Lo (28)|