A whirling dervish

[Duik]

No swirling dervish in Oasis.

There was a mob that whirled and changed form to something like a dark elf spy.
On death the normal dervish emoted something like cant.. hold.. form. Then transforms into an extra tough blue con of similar lvl to dervishes.
Handed me my arse on live. May have been either a super rare or an event.