Graveborn Muse has the potential to be several Phyrexian Arenas taped together (although watch out in Zombie decks that it doesn't kill you), and Underworld Connections is basically a Phyrexian Arena that just asks you to sac a land when it enters
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With that, you can then use cards like Knight of the New Coalition, Xerex-Strobe Knight and the bomb Invasion of New Phyrexia to make Knight tokens and go wide
Id expect to see a fair number of copies of Turntimber Symbiosis in Primeval Titan decks going forward
I'll often cast her, immediately drop her loyalty to 2 and kill the biggest threat at the table, and then call it as someone swings into her and kills her
Its slow and methodical nature means it's probably not all the competitive, but it's a cool concept compared to other pod commanders that pull creatures from your library