I doubt Nishi will be too resentful, after all, Kurono and Katou are the only remaining members from his team. Katou actually tried to save him, and Kurono couldn't save him cause he didn't have a suit and was "good as dead."
Originally Posted by Viscious
However, I think he'll be at least momentarily confused. The next chapter should either confirm or put to rest whether he knew Izumi or not.
A man said to the universe: \"Sir I exist!\"
\"However,\" replied the universe, \"The fact has not created in me a sense of obligation.\"
-- Stephen Crane