The oldest of the "old men", Romero Malavar was one of the leading members of the League Militaire on Earth. Romero spends most of his time assisting the cause around the others of the old men. He shows his abilities with electronics when he arrives at Üso's home and looks over several data chips left by Üso's parents. He then installs these into the Victory Gundam's Core Fighter. Romero is critical of Üso when he fails to pursue his enemies, advising him that in war he must kill his foes he also says "You're an expert of a pilot! You've now become a chosen warrior!" clearly expressing his belief of the crucial role Üso will play in their battle against Zanscare, a position that Romero will continue to hold until his death.
When the League Militaire arrives at the Federation Forces Becheyne base Romero further impresses his aggressive attitude by arguing with their transport planes pilot, saying that they should attack the Largaine base and avenge Oi Nyung, the Camion group's leader who was executed by Zanscare.
In space the crew of the Reineforce plan an assault on a Keilas Guilie. They intend to use a microwave weapon for an assault, but realize that this is a flawed plan. Üso poses some questions about it's other possible uses and Romero realizes that it could be used to induce headaches and stomachs to the crew if used at a low frequency. Together they implement the plan.
The last major action that Romero performs along with the other old men is the designing of a new armor upgrade which is used by Üso towards the end of the war when he is piloting his Victory 2 Gundam.
Romero dies in the final battle against the Zanscare Empire, shot by a Zollidia when he along with Leonid Almodovar, fought atop the Reineforce Junior in a crippled Gun-EZ as the ship performed a suicide attack on the Adrastea.