Does this item need a nerf, or is it fine as is?
I think you and an ally, or two allies within 5, would be an appropriate nerf.
You or an ally is a little too much of a drop.
I think people should be cautious with nerf proposals here.
The reason is that the game just got opened up to any WotC source. Because of that, new PCs will automatically start acquiring items, feats, and powers which were not previously available.
Power creep will start occurring by definition.
But if people start trying to nerf everything that sounds a bit strong, we'll start having little nerf wars right and left.
Since WotC is already nerfing the really strong stuff via Erratas, I suggest that we continue to let them do that job. Bloodclaw, bye bye.
Here on the boards, we should only nerf stuff that is obviously broken from nearly everyone's opinion (and even there, WotC will probably get around to nerfing it sooner or later).
For example in my adventure here, Healer's Mercy just healed over 100 hit points of damage in a single round with a single power. The encounter went from scary to ho hum in a single round. I consider Healer's Mercy to be borderline broken (if not broken, it would be fine as a Daily power instead of an Encounter), but I wouldn't want to suggest to the players using it right now that they get hit with the nerf bat. Sheeva (and River and several other PCs) got nerfed by WotC and it's not fun.
I think we should keep the nerf bat mostly in WotC's hands and reserve it here for the most egregious of offenders.
The Symbol of the Holy Nimbus is strong, but far from an egregious offender.
JMO.
(editted because I cannot spell bye bye)