Dag-Wing is formed when Wing Yoku combines with his Dag-Vehicle, the Wing Liner through the Fusing Combination. He can then combine with his teammates Dag-Armor and Dag-Turbo to form Liner Dagwon, then additionally combine with Dag-Drill to form Super Liner Dagwon.
Design-wise, Dag-Wing is most likely based on Bird Bomber.
During Episode 3, as Dag-Fire was overpowered by the Liquid Lifeform Garos Seijin due to being weakened by its power-draining abilities earlier on, Kai, Shin and Yoku decided to intervene, combining with their Liner machines and defeating the Seijin together. Dag-Wing freezed the Seijin using his Blizzard Typhoon, allowing an opening for Armor and Turbo to destroy the enemy.