@Silver LightningYou dont have to fight gale, from the pic below, if you dont end turn with an unit within the light blue area, gale will not spawn and destroy your team.
@LaocornRestart the game, if you dont get all the legendary weapons you are screwed. (You will not be able to acess chapter 23, 24, and the final chapter [True ending]. You will end game at chapter 22 and get the BAD ENDING.)