Martial Supremecy

One Model in the Unit selected to ill a Prime Force Organization Slot with this Prime Advantage gains the Champion Sub-type and the Duellist's Edge (1) special rule.

"A Weapon with the Duellist's Edge (X) Special Rule grants a bonus to Focus Rolls in Challenges."
In Step 3 of the Challenge Sub-Phase, the Focus Step, if a Player has declared that the Model under their control will use a Weapon with the Duellist's Edge (X) Special Rule or has the Duellist's Edge (X) Special Rule, then that Player gains a bonus equal to the value of X on the Focus Roll.