The Tokyo team (excluding Nishi) will have to step up, even if they are devastated by the loss of Kurono, since most of the Osaka team is unable to fight due to injuries, scared shitless or dead.
I thought that Nishi would do something like this. He has shown in the earlier arcs that all he does is deliver the finishing blow or resort to a surprise attack. But since Nishi's attempt failed, Oka seems to be the one to get all the glory and kill the 100 pointer.
P.S. Goddamn, that Nurarihyon is indestructible. after 2 hits from the BFG and it still manages to come out alive. not mention that it seems that it can still bring on the pain.