With the values you entered that is when it goes left instead of right ?
Also are all the variables float type ?
and can you try this and see what happens.
angle = Math.Atan2(Move.position.Y - Chest.chests[0].Y, Move.position.X - Chest.chests[0].X);
Enemy_Shot tempshot = new Enemy_Shot(Chest.chests[0].minX, Chest.chests[0].minY, Chest.chests[0].minY * Math.Cos(angle) * 0.1f, Chest.chests[0].minX * Math.Sin(angle) * 0.1f, Game1.bossmissile);
Enemy_Shot.shotlist.Add(tempshot);
Also are all the variables float type ?
and can you try this and see what happens.
angle = Math.Atan2(Move.position.Y - Chest.chests[0].Y, Move.position.X - Chest.chests[0].X);
Enemy_Shot tempshot = new Enemy_Shot(Chest.chests[0].minX, Chest.chests[0].minY, Chest.chests[0].minY * Math.Cos(angle) * 0.1f, Chest.chests[0].minX * Math.Sin(angle) * 0.1f, Game1.bossmissile);
Enemy_Shot.shotlist.Add(tempshot);