Special Attack.
The model gains Grind Attacks (X), and can make Grind Attacks as Supporting Attacks, ignoring the maximum number of Supporting Attacks. When the model is not Engaged in Combat, X is set to 1.
At the start of each Round of Combat other than the First Round of Combat, if the model is Engaged, X is increased by +1 (e.g. Grind Attacks (1) becomes Grind Attacks (2)).