I've posted this a few other places, but I honestly feel that not just Sunbreaker, but any super or ability/weapon perk that grants health regen should only be against minions of the Darkness (PvE only). Every Super gains a protective overshield on activation that lasts either 7 seconds max, or for the duration of the super. Of course, I also wanted the Defender bubble to Disentegrate nearby PvE mobs and enemy Guardians, and have a perk that rapidly damages enemies inside the bubble (maybe instead of Armor of Light).