Honestly I would say that song of light should be more powerful. Right now it just doubles grenade cooldowns for allies that are really close. I think it should have a bigger area of effect, speed up healing by 50% for everyone, and maybe add one other buff. Right now its pretty useless compared to radiant skin and fireborn. This could solve the problem of too many fireborns and nobody using song of light. Would make sunsingers very useful in more situations than preventing wipes. Another idea is to make it have the 1 time instant regen health perk for all nearby allies when activated, but not for the caster. Makes it balanced, makes sunsinger a better support class and could add more dynamics.