Calista might not have had enough offensive strength but her excellent crowd control abilities and her magical restrictions more than made up for it.
She had always been a team player who did not shine as bright when she worked alone. Her ability to change the rhythm of the battle, to control multiple enemies at once and an improvisable defence would have been an asset to anyone working with her.
So, any team would have welcomed her with open arms had she shown any intention to join them but she had chosen to be a teacher at the school.
The vines that had just broken ground could already be called trees based on their thickness and strength but were still as malleable and flexible like a vine would have been. They moved towards Kyouko who was rushing towards her in fury.