fe-bruary, post 六: why tibarn didn't kill naesala

So after the little stunt Naesala pulls in FE10, Tibarn makes it clear in no uncertain terms that he fully intends to get revenge:

Naesala: Now, now, Tibarn. I know you're angry, but we'll work it out when this is over.
Tibarn: Not a chance, Naesala. I hope you've said all your prayers and farewells. After I break every bone in your body, I'm going to rip your wings off and feed them to you before you get to die.
[...]
Tibarn: Hmph...fine. You get to live now, Naesala. Once this is done, though, you're a corpse.

And that's not just a throwaway scene. Tibarn repeats this threat a bit later (something "I'll be wearing your beak as a trophy" something, man I love his colorful threats).

But then come the end of the game, Naesala's alive and well and diplomat-ing it up. I have zero doubt that Tibarn was fully intending to kill him, and I've got a few theories on what made him change his mind, with various levels of plausibility and interesting-ness:

( Birdies birdies everywhere )