Tactics for the Swamp (Fortress).

Hmm, just a thought: what if there was an experience-based teleport that sends you to the hydra, you attack, and then teleport back? Although, it's more likely the other way around: you attack with hydras on skeletons, and then teleport the hero behind a wall. Perhaps the hydra's speed needs to be increased (if the enemy skeletons are positioned somewhere in a corner).