Main » Articles » Judge's Corner: Oath of the Gatewatch MechanicsJudge's Corner: Oath of the Gatewatch Mechanics By Judge's CornerPosted on February 4, 2016 Reddit Level 2 Judge David Green goes over colorless mana and the new keyword mechanics from Oath of the Gatewatch. TAGS articles, video, rules, judge, judging, youtube, ruling, mechanics, keywords, community, judge's corner, david greene, colorless mana