[morli]

Looks like we get a gist of Shizu ability. Her ability is Queen of the Mountain's End. She has ultimate control over last wall. The longer the round last, the less the opponent could use their ability and the better Shizu chance at winning. Dead wall is in her control too, being the furthest of the wall. She is the worst enemy for kan user and defensive opponent.

Not only that, she can understand the opponent power the longer she play against them. Then she can negate their ability latter in the game. (It was confirmed when Shizu activate her ability in all of the south round, indicating she can use her ability at will). But looks like the opponent can still win if they playing normally, without depending on their supernatural power.