Carnage marched into the tunnels that made up the darkling nest, their formations were messy and weak in some areas, but the tunnel was narrow enough that it's narrowness was what kept their enemies at bay as they unleashed attack after attack on wave after waves of darklings. And Cole and Cassandra were right in front of the entire thing taking charge of every single step and attack that the rest of the aspirants were taking. Cole would probably say that the fighting in the tunnels were the hardest out of every engagement that have had so far. It was worrisome but ultimately they pushed through and by this point the end was in sight.