The Old Witch feats. An enemy unit fails a command check while inside her feat.
Durring the opponents turn, if the unit cannot make a normal advance outside of her feat area, the ones left inside the feat suffer the POW 14.
"A fleeing unit must run...if they cannot run they must make a full advance..."
That means that they can choose to advance 0", but that is still an advance and triggers the POW14.
Just something nice to know for you Old Witch players.