Although 400% health regen has its uses, the Power regen afforded by this ability has enormous implications. 400% power regen essentially will allow a group to spam their logos abilities with little fear of running out of power. It is highly effective when used with a Guardian's Vortex ability because he can pull surrounding enemies near him almost non-stop while the regen wave is up. This allows groups to focus their fire into a concentrated area and allows the medic to join in the fray thus regaining more adrenaline to reuse Regeneration Wave.
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