Marteen was a descendant of one of the first Tok'ra spawned by Queen Egeria at a time when their genetic memory was still close to that of the Goa'uld. Although he was not a Goa'uld, and indeed would bristle angrily at such implications, that same anger would also cause him to be set apart from the majority of the Tok'ra who were much more placid beings. Marteen, as with all other Tok'ra, is committed to the downfall of the Goa'uld yet he would go to much more drastic means to further his goals; he was not above using the same scheming, treacherous means which the Goa'uld were well known for. However, because of this personality 'flaw', it was much easier for Marteen to infiltrate Goa'uld society without attracting any notice. Although this enabled him to do his duty with much more ease than other Tok'ra, it also set him apart from them as they did not condone his nature.
Marteen eventually came into Apophis' service by murdering another Goa'uld in secrecy and usurping its identity as one of Apophis' underlords; this was but one of the actions which proved the lengths to which Marteen would stoop to fight the Goa'uld. Whilst in Apophis' service, he accompanied his 'master' to a mining planet which Apophis had decimated a year before in order to assess the progress of a new naquadah mine which had been built since the uprising. However, whilst they were there, they were attacked by a group of human natives who were still attempting to fight against their oppressors. During the attack, Marteen's host was fatally wounded by a spear before Apophis' Serpent Guards managed to slay all but one of the humans who they brought before their god.
The last of the rebels, a man named Nyklos, spat at Apophis and cursed his name even as Apophis brought him to his knees with a Kara kesh. Marteen, impressed by the man's resilience and hate towards the Goa'uld, asked his master for a favour; to let Marteen take the man as a host in the place of his current wounded one. Apophis, amused by the idea of forcing the human to serve the Goa'uld against his very will, allowed the blending to take place. At first, Nyklos fought the blending, but he soon realized that Marteen hated the Goa'uld just as much as he did and so allowed the process to complete. Over the years, their combined skills have proven to be great tools in their missions on behalf of the Tok'ra.
Marteen was adept at using many spy devices as well as interaction to accumulate information, but his greatest skills lay in creating false papers, orders, and other documentation. Through this, he manipulated the orders sent to Apophis' far-flung underlords as well as using other means of subterfuge to reduce the effectiveness of his 'master's' forces. But, when more drastic means were called for, Marteen was also effective with explosives and also had a particular knack for slipping weapons as well as other items past even the most diligent and loyal Jaffa. Although the other Tok'ra dislike his methods—some have even been known to mutter darkly that he too closely resembles the Goa'uld—none can truly argue with his results. (RPG: "Living Gods: Stargate System Lords")