|“||Only brute force can rule the regions! Fools like you will only understand if it's beaten into you!||„|
Mondo is the main villain of SaGa Frontier, acting as the antagonist in Lute's storyline and having a minor role in the other storylines.
Mondo was originally a Anti-Trinity activist, along with Lute's father and Captain Hamilton, and a close friend of Lute's father. Mondo, however, craved for power, and because of this he betrayed his friend, selling him over for Trinity in exchange for a commanding position. He eventually sets up a monster invasion inside Trinity's base to overthrow the current commander, taking up his place.
Having become the central authority at Trinity, Mondo started building his own private army on his secret base in Wakatu, which he built after nuking the place to get rid of it's inhabitants. He was preparing to launch a full-scale attack at all regions in order to conquer them, using his military power and the Spriggan, a giant mec built by Dr. Klein for him. Leonard, a scientist working for Trinity, finds out about Mondo's plans, who then sets up a explosion to kill him. Leonard, however, predicted this, so he uploaded his mind into a mec body before getting killed. Leonard later joins T260G, helping him on his quest to destroy RB3.
Lute, who had just left his home in search of a job, first meets Mondo when leaving Yorkland. Mondo gives him a ride on his ship, though Lute is unaware of who he really is. Lute meets with Captain Hamilton, who tells him about who Mondo really is, initially believing Lute approached her to seek revenge on Mondo. She offers him to join her on the resistance group, as she was preparing an attack on Trinity's base. After some thought, Lute agrees, so they follow Mondo into his secret base, where he activates Spriggan to fight them. After the fight the mec explodes, with Mondo in it. Lute then becomes the new commander of Trinity, though he didn't wanted to.