Idarran seems pretty nuts from what I've seen, in general.
Given his low provision cost you can fit Idarran in a lot of decks. No need to build a deck around him. Worst-case scenario he will bait out a strong removal.
If a card has such a strong effect and is neutral, it should cost more or have a timer. I hope Idarran gets nerfed, even if I crafted the animated version.