Now I know EXACTLY what you're thinking right now: "Oloro
The Gardens of the Badlands oh hi, whats going on in here
That permanent gains haste, "When this permanent leaves the battlefield, it deals damage equal to its mana value to each creature," and "At the beginning of your end step, sacrifice this permanent." If a permanent has in its mana cost, X is 0 for the purpose of determining its mana value
This is exactly the case with the Togekiss engine, as Gholdengo ex played this card for a short amount of time and had a fair bit of success with it
Thing in the Ice // Awoken Horror: That's right, this round features a double-faced card
Even if you reduce the search down to 3 different Zombies and have them revealed when your opponent picks which one you get to keep in hand - the effect is just too strong, when you consider Zombies love to dwell the GY