It can also be somewhat useful in event maps. (Think the 1v1, 2v2 events etc, or perhaps Dragon Temple.)
Aside from a large area antistealth effect it also gives a (very short) powerful bramble effect. (120% reflect iirc.)
Won't do anything on normal map, but it might just knock out a sin if they try to 3spark you in an instance map.
I had this genie skill on my sin ages ago, mostly because it couldn't use stealthpots.