Welcome to Gaia! ::

If this is the pc game hit the ` key and then tgm this is the god mode cheat it gives you unlimited ammo and health

I dont encounter many Reavers, but for overlords, just zoom look at them with a ranged gun, and shoot at them. If lucky, the gun will fall from their hand, and then just vats them in the face. OR. Pop out a large damage melee weapon and melee them to death. If you have paralyzing palm, unarmed them enough that paralyzing palm goes off and knocks them out. It for some reason ends their function to pick up their gun, so you can just take em out with them doing significantly less damage.