Iba indeed never ran away and left Komamura's side after that. He immediately appeared the moment his captain had lost his immortal body and subsequently all his means to fight, to carry him up on his back and carry his will to defeat Yhwach.
What I found most precious is the words Iba said to him afterwards. He reassured him that he did nothing wrong. Words Komamura needed to hear because he basically lost everything and was regretting going down the path of revenge. Komamura is not able to speak but Iba understood what his captain might be feeling at that moment and knew what he should do.
Komamura and Iba have such a close captain - lieutenant relation that I don't think is talked about enough. Until recently I thought iba was his first name. Turns out it's Testsuzaemon and Komamura is on first name basis with him.












