BattleTech Legends: Warrior: En Garde (The Warrior Trilogy, Book One) - BattleTech Legends, #57

'MECHS AT THE READY.Betrayed by his own House and stripped of his rank, exiled Mechwarrior Justin Allard is given one last chance to save his honor-by risking his life in the gladiatorial arenas of Solaris VII. But his newest Game World opponent-more skilled at 'Mech-to-'Mech combat than any other rival-raises the stakes even higher. It's Philip Capet, former mechwarrior in the Davion military-until he was kicked out by none other than Justin Allard before his own unfortunate fall from grace.
Both Justin and Philip face fierce battles, but in the Inner Sphere, where nobles have schemed for centuries to win the ultimate power, those who interfere with the Successor Lords are sometimes called heroes. And sometimes called victims.