By the way: Tokens are also permanents, by definition (specifically, they are markers used to represent any permanent that isn't represented by a card)
What makes Solitude so powerful in Modern is that the format is slow enough and the lack of Wasteland means that youre usually hardcasting them instead of evoking them, which when you combine it with blink effects like the previously mentioned Ephemerate and Yorion, Sky Nomad, is an extremely potent card advantage engine
Lastly, Wrenn and Realmbreakers second minis loyalty ability provides an emblem that allows you to play lands and cast permanent spells from your graveyard
Sometimes you can build an almighty deck thatll crush everyone else in four turns, but if its not fun to play, then its not good
Based on the latest market prices tracked on TCG Stacked, Phyrexian Arena is worth about $4.63 USD
Once your opponent's hand is empty, Geier Reach Sanitarium can close out the game by continuing to trigger Waste Not and Sheoldred, the Apocalypse
