Guardian and impact

[Czarvak]

If I have Royal Guards within range to Guardian Dark Troopers am I correct that if I have priority I can guardian before impact but if my opponent has priority he can convert impact before guardian? Or is impact not a card keyword so that takes president and the impact turns a hit into a crit before guardian? 

[Seth]

Hello,

Impact and Guardian are both resolved during the Modify Attack Dice step. The attacker modifies attack dice first (page 30) during this step, which means they will apply their Impact keyword as eligible to modify dice before any results are canceled by the defender's Guardian.

Hope this helps,
Seth