Celestine eill appears in this time period. And I think if nothing changes too much Praedexes will martyred herself against Kraken. That one is a Living Saint material .
You know Kryptmann is literally the premiere asset on Tyranids we have atm right ? Literally instrumental for us surviving Behemoth. The latter Cordon and then the Gambit is the product of despair, not idiocy. What happened is because he knows too much about the Nids, possibly more than most of the organization. I dont condone him, but this is more of the decision from a man who fight Nids , consumed his life to this, right from the very start ( literally the Inquisitor investigating Tyran after it was eaten. ) seeing the sheer terror of Leviathan