Radiance in it's purest form was abut fast ability regen and enhanced abilities (grenades for days and High damage melee abilties, [u]not self res[/u]) I could easily see Radiance in D2 by making the grenades each more powerful version of themselves (like with voidwalker's chaos accelerant) as well as the melee attacks. That way it wouldn't overlap with sunbracers. Another thing would be to have Heart of the Praxic fire return and give you fast ability regen but only in your well+ one neutral game perk like solar abilty kills give you solar ability energy /dreams