May 12, 2020
Hypothetically, if Season was on the Witch was on the battlefield, and someone cast Master Warcraft, all the creatures that didn't attack that turn would die, right?
That’s correct.
Season of the Witch doesn’t care about why the creature didn’t attack, just that it could but didn’t. It also doesn’t force anything to attack, so casting Master Warcraft just to force a player to not attack at all would be enough to make all of that player’s attack-capable creatures die to Season of the Witch’s end step trigger.
