Type: / Power: -- / Accuracy: 90% / PP: 5 / Target: Single adjacent Pokemon / Category: / Priority: 0
"The user teaches the target one of its on moves in place of the targets last move. The move can be used during battle until the Pokémon has fainted"
-So like a reverse Mimic except it lasts for the entire battle. The move of yours it teaches the target is random except it cannot teach the target Tutor.
-Turn 1: Haxorus used Surf on Blissey, Blissey uses Tutor, Haxorus now knows Egg Bomb in place of Surf. Turn Ends
Interesting move...seems like it could be devastating to certain Pokemon, especially choice Pokemon. But like in your example, would Haxorus have Egg Bomb the entire game, or until it switches out?