BACK ON TOPIC: It's absolutely busted. My playgroup allowed it for awhile and it was just too good of a card. Obvious synergies with Magosi, the Waterveil allow for easy infinite turns. It's just really good. Reactivates persist and undying, puts counters on things that are sometimes difficult to get their counters, like Myojin. It's just a really good combo piece.
Unfortunately every try hard from Sacramento to Shanghai preaches from the top of their 27 lands + Mana Reflection that Tooth and Nail and Time Stretch are fine to play in the same turn but Armageddon is unfair.
Im only using it as a bad power conduit. Im building a charge counters deck. I also have played Form of the Squirrel before. My opponents were good with it because they can kill me easily. However they were vehement against my giant fan because i was taking additional turns with my Magistrate's Scepter
{SCD} GIANT FAN