Is Felray's ability global or local?
Felrey's ability will only trigger when she is present in the combat.

From the section on P12 of the Shards of the Throne expansion rulebook "Using Mercenaries In Battle":


  Any Mercenary abilities that work during battle may only be used if
  the Mercenary is participating in the Space Battle or  Invasion
  Combat.


You could argue that "at the start of a battle" should not technically count as "during a battle" I suppose, but that sounds like excessive rules-lawyering to me!