Enker is an assassin-based robot whose sole mission is to defeat Mega Man. He is a member of the "Mega Man Killers" and originated from the 1991 Game Boy game Mega Man: Dr. Wily's Revenge. Enker's Mirror Buster allows him to absorb shots into his Barrier Spear and fire them back at Mega Man as either small buster shots or large waves, depending on the amount of shots taken.
In Mushroom Kingdom Fusion, Enker is one of the eight Portal Masters found in the Wily Portal Chamber featured in Wily Citadel, which is the final level of World 3. The player must defeat all eight "Portal Masters", including Enker, without dying, or be forced to fight all of them again (although an extra life is provided beforehand to prevent the player from running out of lives). After Enker and the other Portal Masters have been defeated, a path to the final checkpoint will open up. Inside the player will enter one last teleporter, which will transport them to the boss room and the final battle against Dr. Wily.