It's everyones favourite tree; bringer of tears, hate, and misery.
What Does This Deck Do?
Dizzy Spell is not spectacular on its own but at least reduces damage and gives you the ability to Transmute for most of the cards in your deck.
Remand is good here because it's cheap and lets you draw.
Vapor Snag and
Clutch of the Undercity give you bounce to remove threats and lower your opponent's life total for when you get your combo off - and, as mentioned before,
Clutch of the Undercity has a bonus Transmute ability.
Sideboard
Main threat to sideboard against are cards like Extirpate or Surgical Extraction. Split Second is a tough ability to beat but there are ways around it. Primarily, we're looking at Den Protector and her Megamorph ability - it doesn't use the stack and you can use the mana abilities of Chromatic Sphere or Chromatic Star to pay for the green mana you need to pay the Megamorph cost, since mana abilities also aren't blocked by Split Second. Once she's flipped, you get your Tree of Perdition out of your graveyard before Extirpate or Surgical Extraction resolves. Yes, it's circumstantial and yes, it isn't going to answer a turn 1 Surgical Extraction right after they Thoughtseize it from you, but it's the best chance you'll have with this deck at mitigating the risk other than Leyline of Sanctity which also happens to be in this sideboard.
Not much probably needs to be said about Leyline of Sanctity. Good against discard, good against burn, circumstantial at best to get it in your opening hand but at least you can cast it with chromatic artifacts even though they're out of colour.
Dimir House Guard is a good multi-use card. It Transmutes for the same CMC as Clutch of the Undercity so you can use it to get Tree of Perdition or Triskaidekaphobia. It also has Fear and regeneration so that you're not totally out of the game if all of your trees are gone.
Hour of Eternity is a means for you to get your Tree of Perdition back as a 4/4 in case it got countered or destroyed. Once it's back, you don't need to worry as much about also casting a Diminish since you can tap it to take your opponent down to 4 life which is still brutal - and this deck has plenty of cards to take out 4 life. Also, Hour of Eternity can be used to bring back a Den Protector or Dimir House Guard if you've sideboarded them in - and both work much better as fighting creatures when they're 4/4's.
Maybeboard
I have Stratus Dancer in the maybeboard because, like Den Protector, it has a Megamorph ability you can use to counter cards like Extirpate or Surgical Extraction because it gets around Split Second. Except Stratus Dancer is in colour for this deck so if you're sideboarding out chromatic artifacts, Stratus Dancer might be a better choice so that you don't have to worry about producing green mana.
