Codex was born into an already broken pack. The lead male and female had been killed off by rival leads in a 'personal battle'. This left the young & unexperienced yearlings to try and care for a new litter born by an elder sister in the pack, who left shortly after giving life to the young one. A terrible life she gave them. Codex and her littermates endured watching the members of the pack die off from hunger. Hunger that was brought upon them due to the responsibility of feeding the youngest first.
Things became so dire that the pups would be starved for a few days in order for their older siblings to be able to survive as well.
By the time Codex was a yearling, there was only three of eight wolves left in the pack. Those wolves being her, a brother of hers and their older sister Nook.
Now, how'd her and Ruvera meet?
While on a small patrol in her temporary territory she wandered off from the usual trail (outside of the territory) which ended in her stepping into a trap.
Ruvera had sent out Striker on a hunt.
Smelling blood in the air he went to check it out. And there was Codex, rolled onto her back and grinning. (tbc..)