Im all for that it would kill the 0 mana whirlwinds that usually cause these crazy combos.
Iirate that would kill the card like Pagle.
I still don't think so. There's a huge different with a 2/0/4 and a 6/5/5 in terms of dealing with it immediately. I think Thaurissan's effect is just too powerful to be as consistent as it is, and if it often royally screws up a turn because it was awkward to remove, it would still be a fair and totally constructed playable card. Similarly, Sylvanas doesn't always get her mind control, but she makes things difficult. Thaurissan's effect is arguably stronger.