Once it had been established that as long as Kat didn't go too overboard with the demonic energy things had calmed down and settled into a routine. After recovering her energy Kat got back to work, chipping away at the ice wall until gave way to unfrozen rats, blasting it again, and keeping on.
At some point Kamiko had decided to be more efficient about things. She'd put together a bunch of ice in the shape of a snow shovel before freezing it together. She kept running her energy through it every now and then to keep it frozen as well, but that was mostly an extra precaution. She only did it because unlike Kat she wasn't really using much energy at all so this little bit of extra expenditure wasn't worth mentioning.