The best Hero Berserker deck right now runs it with Electro Giant, Lightning and Hero Bowler. The most played Hero Berserker deck is a different build with Evo Mortar.
Hero Berserker
Overview
“It's surprising how often she needs her axes sharpened, but then again, if you liked hitting things as fast as her, so would you.”
Ability
Hero Berserker's Savage Survival ability costs 3 Elixir. For 3.5 seconds a Bear spirit emerges through her: she attacks every 0.2 seconds instead of every 0.6, and her Hitpoints cannot drop below 1, so nothing can take her out until it ends. Her hits deal 75% less damage to Crown Towers while it is active.