Bring a well-stamina-trained Rock Drake for mobility, a strong shotgun with plenty of ammunition, backup hazard armor, and powerful tames such as Megalosaurs or Reapers for dealing damage. Ride around the arena to destroy Rockwell’s tentacles with the shotgun, avoiding his energy attacks, then attack his exposed heart and repeat when the tentacles return. Carry a light pet to help handle the Nameless and Reaper creatures that appear during the fight.