How many Game Changers are there
Valley Mightcaller might not be a squirrel itself, but it grows any time a Squirrel enters, and that includes tokens
One sided wraths are always good, and to have a blue one not tied to Krakens, Leviathan et al is refreshing
This is a very powerful card even when played for its full cost since exiling is the best removal type, especially in a format like Pioneer where abilities like indestructible are more prevalent
If a creature is about to die to something unrelated to Vampiric Dragon, then go ahead and spend two mana to put your mark on the creature, and then when it dies, you'll get a +1/+1 counter
Halvar, God of Battle is a beater for a good rate that can really shine in an equipment-focused deck