Heroic levels count?

Hi there! I ve seen people having something like 50k of health or 400+ power while battling at the arena. Does anyone know if heroic levels count in the arena and how much of %? thx in progress

Heroic levels don’t count in arena but as far as I know, the only heroic level or talent that affects arena is the epic affixes on gear or on legend pet such as +2 stealth