So I've never really understood Tree of Redemption, or by extension Tree of Perdition. What happens to the tree's toughness when you swap? I mean, I know it swaps, but for how long? Is it permanent or does it wear off at end of turn? I'm assuming it is permanent, but for some reason that doesn't sit right with me.
I may legit play Tree of Perdition in Commander. Being able to set people's life totals is always borderline-degenerate tech (playing Arbiter Sphinx or the original Sorin will usually get you tableflipping in my local meta at this point), but this card is slow and awkward enough that it might be cool rather than horrible. Tree with boots as repeatable life total sniping starting turn one seems pretty dirty, but also kind of hilarious.
Soul Separator is fun design. Not reeeeally sure what I would practically use it for, but it's cool. And hey, there's how you get someone into range with Tree of Perdition, you use Soul Separator to make a 1/1 flying tree ghost and a 0/13 zombie. Cooooool.