This card is insane. For multiple formats including Vintage (obviously, we'll stick to Vintage).
The ability to function as a Crucible in a format with Dack, Fetchlands, Wasteland, Strip Mine, JVP, Bazaar, etc is obviously absurd.
The -1 ability is secondary but provides versatility and removal of Young Pyromancer, Revoker, Snapcaster, Narset at 1 Loyalty (or 3 in conjunction with a 2 power creature), while still keeping Wrenn in play. It's a bonus on an otherwise strong card.
The ultimate is game-ending in a format that has instants and sorceries that include Time Walk (Retrace and the +1...), Ancestral (draw more lands, keep retracing), etc... You can't pay alternate costs with retrace I believe (since you can only use one alternate cost).
This is all in a 2 mana planeswalker that goes up to 4 Loyalty.