Water Gun Balloon Game Water Gun Balloon Game was a card that I considered in the early days of my cube, but its probably too niche for many lists
This isn't exclusive to your own, allowing you to get a copy of a powerful creature an opponent controls
While there are other planeswalkers that just immediately win the game with Doubling Season (like Nahiri, the Harbinger getting Emrakul, the Aeons Torn), Samut, the Tested offers several different ways of getting the job done by tutoring out Emrakul, the Aeons Torn and Xenagos, God of Revels directly, finding Nahiri, the Harbinger to find Emrakul, the Aeons Torn, or using an entirely different combo altogether like Restoration Angel and Kiki-Jiki, Mirror Breaker
With all of this combined, Prinzessin is not a fun card to play against
Then it dies, leaving behind two colorless Wurm Artifact Creatures in its place: one with Deathtouch and one with Lifelink
Arguably Blue at its bluest, three mana allows you to hunt down any three cards in your library