Nosferatu

Nosferatu is a Boosted Skill.

Nosferatu halts a Lily's aging and also the decrease of her Magi capacity. However, should the boosting process be unsuccessful, the Lily will inevitably lose her sanity.

It's unknown at present whether any Lilies have ever been successfully given this skill. Supposedly, Takamatsu Shiera may have been, but this is nothing more than a rumor.