For our purposes, it's close to a perfect land: It enters the battlefield untapped, giving us a turn-one Siren Stormtamer or Deadeye Tracker while helping us cast a two-drop of the opposite color on the next turn, like Kitesail Freebooter or Kari Zev, Skyship Raider
You're paying 4B to start with, and then you also have to sacrifice a creature with high power to make X a relevant value
Given how powerful Master Ball is, I would imagine this will be the go-to ACE SPEC pick for most decks.
However, it requires you to cast noncreature spells or cards that provide oil counters in order to enable its tap damage
This doesnt sound like much of an issue at first
Just like the Timetwister, this is a Power Nine in Scheme form, ready to bust things up