I'm happy with my progress. Last time this event happened, I could only clear the one stage of the 4th level where multi-attack girls work best. This time I was able to clear all stages of the 4th level and beat the first 2 stage Nidhogg. However the last 3 stage Nidhogg is still too much for me. I'm able to get to 3rd level of the monster with my 2nd group, but the remaining girls can't do enough damage yet. Still, very happy.