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[CMM] Pearl Medallion
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So looking at some quick and dirty math, if you have ~40 enchantments in your deck you'll have about a 98% chance of getting 1+ off her first ability, 85% for 2+, 59% for 3+, then 28% for 4+, and under 10% for 5+
Definitely seems good, especially if you can blink her. The tap ability is cute with how she's basically the only one who can wander Duskmourn without issues, and it can definitely cheat some rooms open, but it seems a lot more niche.
There are 16 rooms cards in the set so far. If you get Central Elevator you can tutor room cards, and you can use her to reset that room for repeat searches. Promising Staircase is also an alt win con for her that comes attached to your tutor engine and lets you better set her up for an ETB trigger through surveil 1 on upkeeps.
First tutor would likely be Bottomless Pool so you could pay {U} to bounce her to hand, recast her to refill your hand, and then following turns to reset a bounce engine.