Rare Skill

Rare Skills are powerful abilities that many Lilies are able to make use of as a personal expression of their Magi. The vast majority of Lilies have a single Rare Skill; as each Lily's Rare Skill is a reflection of her fundamental nature, it is not thought to be possible to have more than one, with only a single exception having ever been observed.

Each Lily's Rare Skill is classified with the rank C, A, B or S depending on its power. With practice and dedication, Lilies can advance their Rare Skill to higher ranks. S-rank users of Rare Skills often gain additional abilities specific to the Rare Skill in question.

Rare Skills are the subject of ongoing research, and some powers formerly thought to be Rare Skills, like Charisma, were later recognized as subskills.

Awakening Rare Skills
Lilies don't necessarily have their Rare Skill yet when they first enroll in a Garden and become a Lily. They awaken to it at some point, often during their first year of high school or even later (though some Lilies have awakened their Rare Skill as early as kindergarten.)

If a Lily has not awakened her Rare Skill yet, it's impossible to tell which one she will awaken to in the future, but Gardens can accurately predict broad categories of skills that she won't awaken to.

A few Lilies never manifest a Rare Skill at all.

Lilies with no Rare Skill are not commonly admitted to top Gardens like Yurigaoka.

Subskills
Subdivision skills, more commonly known as just subskills, have at most 70% of the power of Rare Skills. Unlike Rare Skills, each Lily can have multiple subskills. The Lily with the largest known number of subskills has 7 of them.

All subskills correspond to a Rare Skill, but several Rare Skills (Brave, Circlet Bless, Z, and Zenon Paradoxa) have no known subskill equivalent.

Boosted Skills
Boosted Skills are abilities known only to appear in Boosted Lilies, and never in regular Lilies. They equal, or quite possibly exceed, Rare Skills in power. Unlike Rare Skills, there is no hard limit to how many Boosted Skills a Lily can have, though it is rare for them to have more than two or three at most.

This is because attempting to give a Lily too many Boosted Skills can drive them into a state called "lunacy" in which they attack other life forms indiscriminately, similar to how the Huge do. The risk of this also depends on the Lily's own mental fortitude. GEHENA usually disposes of Lilies who are known to be in this state.

Certain Boosted Skills (some of them specifically when in combination with certain Rare Skills) almost guarantee that the Lily given them will descend into lunacy, with very few exceptions.

Some Boosted Skills, notably Magi-Reflector, are possessed by certain specimens of the Huge as well.