The zero equip cost allows Grafted Wargear to efficiently come down and change the texture of combat, and the cards drawback adds some risk to the equation
Self-Destruct, for example, would have been a nastier component of the already rampant Mono Red, especially with the knowledge that one of the winning moves for it was to blow up a Heartfire Hero using it
3 Counters Golgari is unique in that its Counter archetype isn't just +1/+1, but -1/-1 counters as well
5 Maleficent, Monstrous Dragon Maleficent, Monstrous Dragon is one of the highest-costed cards in The First Chapter
The deck doesnt seem to be a strong contender as of now but these cards all have a high power level and can potentially see play in the future
Faeburrow Elder is a Treefolk Druid with a similar ability, and it gets +1/+1 for each color among other friendly permanents