Until the stance ends, you are immobilized. If an enemy charges you or an adjacent ally through the target area, you may end this stance as a free interrupt to make an attack with an attack bonus equal to your Constitution modifier. If you hit, the attack is a critical hit on an 18-20 and deals an additional +2dW damage.
You may shift one pace as you enter this stance. Until the stance ends, if you are wielding a weapon with the reach property, you threaten all non-adjacent spaces within your reach, but no longer threaten adjacent spaces. When you hit with an opportunity attack, you may end this stance as a free interrupt to slide the target one pace and knock them prone.
If you use a flail to make the opportunity attack, you may grab the target instead of sliding them and knocking them prone. While the target remains grabbed, you cannot use your flail, but may sustain the grab for as long as the you remain in this stance and the target is within the flail’s reach.
You must use a move action at the beginning of each turn to maintain the stance until the end of your next turn. When you do, you may also shift one pace; if you have a target grabbed due to this power, you may pull the target one pace as part of this move action.