That's weird since episode 15 is probably one of the non-action episodes I remember most clearly in Victory.
Shakti is pretty attached to Uso, considering he's the closest thing to family she has left. She makes a lot of naive and stupid decisions, but it's almost always for what she thinks is best for him. Which is why she tries to convince him to not fight and just go back, and then to follow after he does go. As for Fuala, I believe she was being punished for guillotining the League Militaire prisoner in the earlier episode. Higher ups probably wanted more time to interrogate him since he was a notable figure, but she jumped the gun and offed him too quickly.
And that's a morbid way of looking at Uso's actions. Despite the kill count, he's still a naive and kind-hearted kid, who would easily help stranded strangers regardless of affiliation. I really liked the scene where Uso interacted with a hardened dude like Godwald, willing to die instead of just accepting help. It's just so cheesy, I can't help but love it.