Tomb Guardian Investigation

I think this is by design, I beat it without Chewy Yoda being defeated and I am still missing him on round 2.

As much as this update has been a buggy mess, that part's intentional, I think I read it in the unique abilities for the Tomb Guardian

Nah, level 2 Coliseum only had 4 units.  Happened to me and I never lost Choda in level 1

WAI
Each Tier you move up, you lose an ally. You're on Tier 2 so have lost Choda. Next Tier you lose another toon.
Check out the popup text on the second Chevron icon under the Green Progress bar (top right).

When you go up a tier, you lose a character. At T3 you only get 3 characters, so its intended.

I had to figure out on my own that as you go up each tier you can lose one of the five tunes. On tier 3 you only have three tunes. 

Also, the COMs silence on how we're supposed to level these people with their era gear and when the air battles are going to come out or what the rewards are going to be is deafening. Needlessly greedy. Their system seem to be working decently. Nope. Let's can it.

When you go up a tier you lose a character.
tier 2 it's chewy yoda or choda
tier 3 it's asajj