Skirmish

Skirmish is a battle activity in Final Fantasy XIV. The Eorzean Alliance has released monsters onto the islands of Locke's Lie and Turtleback in La Noscea for the purpose of joint exercises between the armies of the three companies. The Brugaire Consortium has generously begun sourcing Giantsgall weapons from Radz-at-Han as rewards for participants.

Rewards
The Giantsgall weapons are manufactured exclusively in Radz-at-Han. They are unique in that, unlike the rewards from other combat activities like dungeons and primals, these weapons can be melded with Materia (Final Fantasy XIV). This is likely because they have been crafted recently, rather than the dungeon treasures made before the advent of Materia melding.

Final Fantasy XIV
It is currently unknown if Skirmish will be in the new version of the game. The trailers imply that the Grand Companies will still be around, so this join exercise may exist as an ongoing effort to unify the Alliance.