Stoneforge Acolyte
Oath of the Gatewatch — uncommon
Creature — Kor Artificer Ally
Stoneforge Acolyte rulings:
2016-01-22: To activate a cohort ability, the Ally with that ability must have been under your control continuously since the beginning of your most recent turn. Informally, it can’t have “summoning sickness.” However, the other Ally you tap can be one that just came under your control. (Note that tapping the second Ally doesn’t use [the tap symbol].)