The static boosts are nice, particularly for the likes of Norman or Marie that can use the as well. But it's usually a waste to get Ikiaq just for the stat boosts, particularly since mystics have no shortage of good allies. You'd usually be better off getting Arcane Studies if you're particularly enamored of the two stats; it'll save you a Charisma as well. No, what you really want Ikiaq for is the ability to cancel basic weaknesses.
Mystics will rarely need to use Ikiaq's ability for themselves. With Deny Existence and the worst draw of all the classes, Mystics don't worry much about their own basic weakness. The draw that they do commonly use (Scroll of Secrets and Arcane Initiate) can't draw basic weaknesses either. Ikiaq is better for your friendly fast drawing rogue or seeker, who is likely to draw out their deck and see their weaknesses more than once. It's for a support mystic that's willing to give up their Ally slot and 6xp for the good of the team.
Y'know about all those degenerate rapid-cycling big hand seeker decks, and how the only thing holding them back is nasty basic weaknesses like Through the Gates or Amnesia? With Ikiaq, they'll have nothing to fear at last. The last barrier to true seeker supremacy is finally broken!
You'd think it would mitigate Doomed or Offer You Cannot Refuse, but in practice it doesn't do very well against those two as the "upgraded" forms are no longer basic weaknesses and can't be cancelled. All it takes is drawing them before IKEA is purchased or before he's played, and he'll be useless against them henceforth.
He also is much more useful in Standalone mode, where you have more weaknesses in your deck and haven't built your deck to mitigate those weaknesses.