Weird idea for a support set...

[biostem]

I don't know if you'd call this a luck-based set or something different, but the idea is this - all your ally-targeting powers actually require a tohit check against that target.  Whether you hit or miss, (and by how much if that's possible), determines which effects you generate.  Further, the set could include a build-up like power, or perhaps a toggle, that allows you to invert whether a hit or miss determines the effect.  I was thinking this set could focus on some neat abilities - like maybe some ability to grant allies temporary crits, or perhaps even fun stuff like utilizing the mirror option for phantom army to create temporary duplicates of allies.  It could grant absorb and maybe even generate some sort of draw-in or reverse-repel effect seen in battle axe.  You could have a rare effect that simply opens a rift to summon a Lusca tentacle to deliver a whack...

[Vanden]

I don't think tying the effects of powers to something random and uncontrollable like a hit check is a very good idea, but a sort of Yin-Yang set where every power has two possible effects, where you switch between them with a toggle or something, could be cool.