All the game says is that these two kinda go way back, so I sorta filled in the blanks.
I can't be the only one who ships these two.
Even in the most dangerous of battles he knows he can count on her to back him up, and she can always expect the same from him.
Sometimes he charges through to the front lines, bow poised to drive an arrow into the enemy's heart, and he's aware of her presence behind him, guiding him from above. She tells him not to be careless and even though he knows she worries when he's injured, he can always trust her not to start panicking. Katua is always collected like that.
When she flies on ahead to assess a situation or stop a thief from robbing the villages, he remains far enough away so as not to seem overprotective but close enough that if she finds herself in a tight spot, he can lend her a hand. Warren knows she didn't become a White Knight of Macedonia by being weak, but he also knows she didn't become one by refusing any and all help.
Sometimes it seems odd that they've known each other for as long as they have. They met when he was a simple village boy who got lost in the forest, and even though it was embarrassing to be saved by a girl and her pegasus he'd always been quietly grateful to her. They kept in touch, even when he traveled the world as a mercenary and she was knighted by Macedonia's royal family.
When she discovered him working for the enemy, it was that day in the forest all over again, but this time he was so happy to see her he couldn't be embarrassed for to long.
When everyone else has retired for the night, they sit by the dying campfire, talking about anything and everything. Their past, the present, and sometimes the future.
"What do you plan to do when this is over?" she asks. He gives her calloused hand a gentle squeeze.
"Whatever I do, I won't be leaving Macedonia again, that's for sure."
She leans her head on his shoulder and smiles.
"Good. I can't imagine never seeing my favorite partner again."
In life, he'll always be able to count on her, and her on him.