Dread Shaman's Expunge

[Lo5er]

I've noticed that when talented and cast on self the shaman's expunge reduces his own mana. Not sure if this was intended but seemed like it shouldn't.

[aegir ravenking]

Guessing you mean while you have ancestral fury caste. But yes, friend or foe it will remove every spell on the unit, and, when boosted, remove some mana.
It is known, but I don't remember if Yak said it was fixable or not.

As a side note, every spell includes ancestral fury.