Exoprimal

To get this achievement you have to beat the last story mission in which you fight Durban/Leviathan controlling the Behemoth Exosuit in a large arena. You get the last mission after getting story cutscenes D-01 - D-20 that play automatically after games. The Analysis Map is not necessary, but if you're like me and interacted with the Analysis Map whenever you could, then your progression will be 99% before going into the last story mission! (Credit to Stk I for the clarification!)

The mission will have you and the other team working together to complete objectives and ultimately defeat the boss. Mission Time 23 minutes, 35 lives available, and long cutscenes!

In the boss fight you’re not fighting Durban/Leviathan directly, but doing multiple sets of Area Defense which leads to the boss having their weak spot exposed for everyone to attack.

The mission objectives will be VTOL Defense and Area Defense + usage of the Omega Hammer. (With Dinosaurs spawning endlessly)

Mission Objective - There will be 3 sets of Area Defense, and when the devices are full, an Omega Hammer will spawn and someone will have to carry it and smash the barrier device (by holding ) that is located on the bottom of the map. This will make the Vortexer (Item used to expose the boss) available to pick up, and someone will have to carry it to the boss on the top of the map. It’s used the same way as the Omega Hammer, get right next to the boss and hold , and then the boss will be vulnerable to attack. (3x)

Note - When carrying a Omega Hammer and the Vortexer you can’t run, so it’s a slow walk towards the objective.

The person carrying the Vortexer will be targeted by the boss, so I recommend having a tank to carry it, and or have someone shielding and healing the carrier. Although in my game, whenever the carrier died someone else would pick it up and continue towards the boss!

Tips -

Watch out for the Behemoth's instant kill laser that he will fire at one of the defense areas, there will be a warning on the screen and you have a few seconds to move out of the way. Afterward, the defense area will be on fire for a few seconds! (Roadblock will be able to tank the laser, may also be possible with the other two)

The Behemoth will sometimes float over to a defense area and create a force field in the area that will push out anyone inside, depending on where you're standing you can be knocked out of bounds! In order to remove the force field and resume the area defense, you must destroy the 4 flying force field drones rotating around the field. (Very hard to reach with melee exosuits)

Behemoth has a rocket attack that locks onto you and attacks from above, but you can avoid it by always moving. He also has a lock on/homing purple lasers too, but you can hide behind the cover to avoid it.

Mission Layout -

Starts off with the first Area Defense, and is just device A located on the bottom. (1 Barrier to destroy) (Carry and use Vortexer on the boss) After this comes VTOL defense. The VTOL will land on the bottom right and then land on the bottom left. Afterward, you can attack Behemoth's weak spot.

After the cutscene where Leviathan takes over Behemoth, he will start charging up to do a Super Nova attack. The lower portion of Behemoth will be glowing, this is a DPS check, and enough damage must be done to stop it! This attack is an instant kill on everyone! (Avoidable if in spawn area)

Note - The DPS check might happen every time the Barrier devices are destroyed and the vortexer becomes available for pick up!

Next is Area defense back-to-back.

The second Area Defense has devices labeled A and B that will be located on the top left and right of the map. (2 Barrier devices to destroy)

The third Area Defense has devices A, B, C, and D which will have additional devices on the bottom left and right. (4 Barrier devices to destroy)

The boss will be defeated after the 3rd Vortexer!

And that’s it for the final story mission!