Ludina, also known as the Ice Witch, is a supporting character in Witch Spring 2. Her subplot is optional starting in Chapter 3 and so it is completely possible to never meet her in the game.
As Ludina destroyed the Icy Fields village by her own hands, she consider herself a grave sinner for killing countless lives. As such, she was worried that she can never be forgiven since the ones who can forgive her were dead. Luna then proceeded to forgive her and tell her to stop feeling guilty about herself. After that, Ludina told Luna that she need time to prepare herself before she comes out.
Not many of Ludina's abilities are shown, but it is known that Aeris and Panda Kum are her Guardians. With the epithet "Ice Witch" and as the one who wrote the Ice Spellbook, it's implied her forte is ice magic.