Sliver Legion and The First Sliver are the cards that are going to benefit the most from encore
In particular, copying Terror of the Peaks or Savage Ventmaw with Miirym sounds amazing
It might seem like an upgrade, but giving the opponent two treasures can sometimes be way worse for you than giving them a 2/2 flier
Geist of Saint Traft 2.6 Power 3.4 Support 1.9 This guy offers a lot of punch for just three mana and being hexproof is of great help with his fragile body, both for safe equipping and avoiding spot removal
Selvala, Heart of the Wilds This three-drop mono-Green legendary Elf taps with a Green for mana equal to your highest-powered critter, so at least 2 with her counting her own 2/3 body
All you need is a way to buff him up and land a hit, and you're off to the races with an instant army that replenishes itself with each attack, or even grows exponentially True, Shroofus will mostly see play in the 99 of other, multicolored decks, but he can make for a powerful commander all by himself