You can stop the regenerating health simply via mod. While the champions only gets stunned for 3 seconds, the anti-regen and anti-teleport effect which is also caused by the mod (what some people seem to miss, yet the mod clearly states in the description) can be spammed regardless if the champion is stunned or still in his stun cooldown and moving. You don't need anarchy at all. You just need to spam the champion with the handcannon EVEN after he is stunned and tries to run away.