The strategy to defeating Veytharion is to keep Ol' Tessie from being destroyed, and constantly ram into him to deal damage. There is no time limit so the key is to be patient and wait for all missiles to be fired before going in for an attack, ensuring you do not take a lot of damage. If you are in a co-op game, one person can be on the DG-2 Turret during the entire duration of the fight, constantly firing at Veytharion for additional chip damage.

Once you have completed a phase, his Golden Underbelly weak point will become available where you can use the DG-2 Turret, Necrofluid Gauntlet, Ray Gun, and Ray Gun MKII to deal significant damage to the boss. The primary focus should be staying alive, with damage coming second, the entire fight is determined by how well you can maneuver Ol' Tessie, and avoid his attacks.

For a complete and more detailed guide for the entire boss fight, you can view our main quest guide to get a complete understanding of the entire fight, and how to survive.