An eye from the gap targets the enemy. It becomes a stationary platform that offers supporting fire. It follows a designated path, so it can be regarded as one of Yukari's familiars.
214B/C, B spawns a purple gap while C spawns a red gap, higher levels lengthen the gap's life, useless unless Yukari successfully attacks the enemy; once upon receiving an attack from Yukari, the enemy gets attacked by all purple gaps. The red gaps attack, when the enemy is in blockstun. Since a red gap drains 0.5 spirit orbs on every Level, it serves well to crush the enemy's guard. On Level Max, you can easily combine purple and red gaps, so that the enemy is instantly attacked by the purple gap, once her guard is broken. But bewares, if Yukari received an attack from enemy, all eyes that spawned will disappear.