O'seph was a human naitive to Pangar, and a loyal ally to the Tok'ra. O'seph is naive, but smart and empathetic, and he was desperate to fight the system lords in any way he could.
O'seph volunteered for an infiltration mission on behalf of the Tokra, unforunatly the mission against the forces of the Goa'uld Malinalxochitl was poorly thought out, and had relatively no preparation or reconnaissance done in advance. When things eventually went wrong, O'seph had to make a break for it and run for his life... that resulted in him becoming stranded and without support in a particularly swampy region of Zonus, which was itself already mainly a swamp planet... That left O'seph just focused on surviving, exploring, looking for allies, or any other opportunity to get back to Pangar to continue the struggle.
Within a month, O'seph found his way to a small and primitive town, but that town (Jarlal in the local tongue) was deep within a sprawling everglades like swampland, in order to keep a low profile he joined the folk of the town as a healer, and occasionally a huntsman. O'seph was just using the excuse of "going hunting" as an excuse to keep searching the swamp for a way off of the planet.
It ended up being years before O'seph found an old crashed Goa’uld ship. And in that time, the environmental stresses of Zonus had taken a steep toll on his body, leaving him emaciated and weakened. Regardless he eventually he got the ship's communication systems back online, and with that he called for help, and finally got back to Pangar.
O'seph's body was physically failing by the time he got back to Pangar, but in the time since he had been gone, many things had changed dramatically, including the Tok'ra finding a cache of Prim'ta that were previously spawned by Queen Egeria and are now being used to create the synthetic tretonin used to free Jafaa from their dependence on Goa'uld symbiotes... The Tok'ra of Pangar had also formally allied with the Tau'ri. The surplus of new Tok'ra Prim'ta gave O'seph a second chance. It allowed him to become blended with Tal'rael, one of the mature Prim'ta of Egeria, and this ended up saving his life.
However, because of the limited amount of genetic memory (if any) that is passed on to the new Pangaran Tok'ra, the blended combination of Tal'rael/O'seph cares more about fighting for what's right, and defeating the Goa'uld, than he does about his own mortality, or the impact his death would have on the ever dwindling numbers of Tok'ra in the universe.
After discussing what had happened to him, and his shortcomings as a spy, the other Tok'ra gave him a new mission, to enlist with the joint initiative at Phoenix base, to see if there was a different way that Tal'rael/O'seph could help resist the system lords.
After completing his basic training in Tau'ri arms and tactics at Phoenix base, O'seph is optimistic and enthusiastic to be assigned to a team, and do what he can to free all worlds from the subjugation of the Goa’uld.