She is not
that bad. Even, not bad at all. She has black tier stats all right, and her skill gives her an unique niche of anti-paralysis.
But, she is a event unit, wholly unupgraded one at that (read 0/5 CR), and so costs leg
and both arms to deploy. And, her skill does not feature power multiplier (only range), so she is less suited for the burst healing. Her AW ability is
major healbomb, but plat
and free gold healers have something like that already.
And, most importantly, there will always be a hope of her event finally hitting our shores, what weights heavily on her status as premium unit.)
Oh, and there's also the little thing that Saint Illys, whom she replaced, is simply outright broken, outrageously so, as far as healer/support goes