Ako's artifact is not used for healing though
I think it's mainly for buffing the party rather than heals them. Maybe if we're going to group them, it will be in support group rather than medic.
If Chizuru's ability is indeed healing, then it might be more useful than Konoka because...well, Konoka's healing spells will take too long (remember the first scene where Negi&party arrived at Mundus Magicus?
) but Chizuru only need to stick her leek to someone's butt
