Unique Plantaur. Lily can be found on forest tile events but only if you're Evolution or Creation. Her events consist of Lily requesting sexual relief and consenting raises the MC's sex skills. After a number of times you get the additional option of recruiting her, but there's benefits to her repeatable events.
Choosing to give her a blowjob fully restores the MC's mana, giving her a handjob rewards you with a Strength Herb, and getting fucked by her takes the least time letting you recruit her faster.
Lily's Magic makes her an excellent hatcher, and all her sex skills cap at Master making her a very efficient sex trainer. Combined with her good looks, she's also a prime candidate to put in the Brothel.
If you do recruit her, Lily's powerful Magic makes her a decent support character, and her Refreshing trait also makes her a choice pick when a unit needs lust removal. However her otherwise weak stats and small stature makes combat dangerous for her. On top of that she gets a Consumable slot instead of a Weapon slot, making her further unsuited for battle. It's far better to get Refreshing on another party member and leave her at home where she can make herself more useful.