From the Comprehensive Rulebook 4.0, page 16:
special ability:
Besides events, other types of cards may have a phase action as a part of their game text called a special ability, which may be used only while the card is in play.
He may use skirmish events during his skirmish, as they are not special abilities, but not his own text (during his or other skirmishes) or skirmish special abilities on conditions, artifacts, etc until the start of the regroup phase.
It would work well for a beefy elf vs a weaker minion (maybe only 1 vitality left?), especially if you've got a pump in your hand just in case.