If it's dinner you're after... I'll feed you a length of iron!
After leaving the Orbonne Monastery in Chapter 3, Ramza encounters Luso being chased by Behemoths in Zeklaus Desert. Ramza, knowing Luso cannot defeat them on his own, helps him, and together they defeat the Behemoths.
Luso explains he is a Game Hunter, and he is looking for his friends. Luso asks if he can join Ramza's party in the hopes of finding his friends, and Ramza gladly accepts.
Luso's job class is Game Hunter, which specializes in hunting monsters. His job is essentially Ramza's special Squire class with an innate Poach; he comes with all of Ramza abilities, including the ones he learns in Chapter II and IV. He also can learn Ultima in the same way as Ramza can in his Squire job.
When fought in the fourteenth Rendezvous battle: Brave Story, he is level 99 and starts with 71 Bravery and 63 Faith. He is equipped with the Icebrand, Crystal Shield, Thief's Cap, Luminous Robe, and a random accessory. He comes with the Huntcraft command, as well as the abilities Reflexes, Tame, and a random movement ability.