Brom loves war and sacrifices his own life for his robot creations. The Milites leader wanted to stop the war and forbade using magitek armor designed for war and made a crystal jammer with the corpse of a Secundus l'Cie. By controlling the White Tiger Crystal, the Milites leader held the l'Cie in his hands. Brom became angered and created the machine to stop the crystal jammer.
Once the White Tiger Crystal is free, Brom became the new Secundus l'Cie after Machina Kunagiri to drive the robot he loved on the battlefield.
Brom's special attacks are similar to Qun'mi and Qator Bashtar who were using MA and their firearms to attack. He can lock on to targets by shooting them with his dual cannons. His strongest skill is to shoot a powerful laser beam, similar to one of Nimbus's special attacks but more powerful.
This form requires Nimbus 3★ Mythic and 30 Mecha Augite Shards; the shards are obtained in the Augite Trial within the Augite System and winning at the Thrones of Paragon once randomly. This shows a scene where Cater, Ace and Cinque encounter Nimbus before he wipes out everyone in his way. When everyone was defeated including both Kurasame and Kazusa, Nimbus uses the three MA to combine with his power to transform into Brom and was witnessed by both Zhuyu and Caetuna before he strikes him out with his two-handed axe but it does not effect on him due to his high durability. The battle between Brom against both Zhuyu and Caetuna in a handicap match begins and Brom eventually prevailed. Once Brom was acquired, it shows a different scene where Nimbus come across the MA robot. He immediately transform into Brom once he enters inside his robot.