There we have it: Season 12 Mary Winchester won’t be a trick or a dream or even a ghost.
Castiel certainly won’t be much help if Lady Toni continues to banish him with blood sigils.
Unless Mary forgot all of her hunter training during her time in the great beyond, she could be a perfect ally in helping Dean to rescue Sam.
Considering that Sam ended Season 11 having been shot in the Men of Letters bunker by Lady Toni Bevell, Dean may need all the backup he can get when Season 12 kicks off.