It's no different than a Blade Dancer with Hungering Blade (health recovery begins immediately after a kill). Sunbreakers have the same skill but it activates when you kill anything with a solar ability (so it activates when using a charged melee attack to get a kill or a solar grenade kill). Blade Dancers already have such an insane armor buff when using their supers that most of them don't run with Hungering Blade, but the ones who do literally can't be killed while they're using their supers, as long as they're getting kills, unless someone else shuts them down with a super of their own. The point is that it's fair, it's balanced, deal with it.