The sword does take up 2 spaces, but actually the sword in the stone could be set to where you can walk behind one part and stop walking into the other, that way you can use one event for the for sprite. Just go to the tileset manager and set the sword sprite to be like so
top of sprite - O, all arrows, 1*, . , . , 0
bottom of sprite - X, no arrows, . , . , . , 0
That is labeld starting with pasability, directional pass, priority, obscuring, countertop, terrain. (Options in the tileset manager)
Try that out. Makes since once you set it up.