If I reveal Stable Cover while Jazz is defending in Alt mode, does this protect his ability from being shut down even if the attacker has Pierce? [Source: WotC]No.
Does Jazz's ability work with Stable Cover? Stable Cover implies that the enemy still has Pierce, they just can't use it, while Jazz states "an enemy that doesn't have Pierce". [Source: Aequitas]As stated, the enemy still has Pierce so Jazz's alt mode ability does not trigger.