Noel had learned so much during the fight. How Stella precisely aimed for a certain spot, how Jonathan controlled his Spiritual Energy or how Zion managed to restrain the demon. It was something he never tried, considering he only had one partner, Anna.
During the trip, Noel kept asking question after question to Stella to the point she was overwhelmed by his drive to improve.
On the other hand, the group also learned about Anna's cooking level.
There was a weaker guy who had the desire to improve and there was a strong girl who almost had everything. They looked like a complete opposite, but they truly filled each other's weaknesses.
Anna wanted to make sure Noel didn't surpass her while Noel had the desire to surpass her. This synergy allowed them to improve tremendously and broke the record of the Demon Banner Army.