Reaper of the Outer Dark The Corsair Prince gains the Rampage special rule, and any unit with the Eldar Corsairs Faction and of the Eldar Jetbike, Infantry or Jet Pack Infantry type may take the Rage special rule for no additional cost. However both the Corsair Prince, and all units upgraded to have the Rage special rule, must declare a charge when within 8" of an enemy unit at the beginning of the Assault phase - if multiple enemy units are within 8", the Corsair Prince's controlling player chooses which is the target of the charge. If the unit fires at an enemy unit that is not within 8" at the start of the Assault phase, it must still declare a charge at an enemy unit that is within 8" at the start of the Assault phase.
Rampage At the start of any Fight sub-phase, models with the Rampage special rule gain +D3 attacks if the combat they are in contains more enemy models than friendly models - count all models locked in the combat, not just those models that are engaged. Roll once to determine the number of bonus Attacks all Rampaging models involved in that combat receive that phase. A model that has made a disordered charge that turn receives no benefit from Rampage.