Mark Rosewater, who joined Matt Tabak on the reveal stream, said battles will be a deciduous mechanic - meaning they wont appear in every set, but the design team can return to that creative wellspring as often as they want to as it isnt tied to a specific plane
It can also tap for colorless without requiring you pay the life tax, which can be significantly important in aggro matchups where you want to preserve your life as much as possible
Nonfoils will drain out a lot slower than the foil versions will, though, but tournament players might well go for nonfoils first
Plus, you get to exile artifacts, creatures, enchantments, and graveyards (or any combination thereof) rather than just destroying permanents and sending them to the graveyard with Austere Command
What I personally am most excited about is the fact that she's a zombie