Whatever Yuyu’s tortured emotional state prior to retrieving her late Schutzengel’s CHARM from Moyu’s lab, it’s all cleared up by the time she joins Riri in the battle against the mega-Huge. She uses Lunatic Trancer in a focused, controlled way, beating back the Huge’s sword-like appendages and helping Riri buy time for the other Lilies.
Riri crosses swords with Yuyu, and her Charisma skill seemingly binds with Misuzu’s within the Dainsleif to neutralize not only Yuyu’s Lunatic Tracer, but the damping field keeping everyone from using Magie. That allows the rest of the Hitotsuyanagi Legion to execute the Neunwelt Tactic. Not only do Yuyu and Riri’s seven legion-mates pass the Magie sphere amongst themselves, but pass it to each and every Lily in the Yurigaoka student body
Riri and Yuyu gladly accept that sphere and add their own Magie to it, resulting in a coup-de-grace that bisects the Huge and utterly destroys it. There are no Lily casualties, and there’s an unintended result to the collateral damage from the Huge explosion: the baths are now al fresco. The Lilies’ post-battle bath is also the first in which Yuyu joins Riri, much to the chagrin of Kaede.
But there’s one more battle to be fought: the ultra-class Huge lurking in the currently dormant nest. Moyu and the director determine that Riri and her highly advanced Charisma ability is the only one who can destroy the boss, but allow her to make the choice. Obviously, Riri accepts the mission, and Yuyu will accompany and protect her. The two are airdropped via V-22 Osprey into what looks like a hurricane’s eye, their descent slowed by a charming parasol.
I figured there’d be a little more mind wrestling among Yuyu, Misuzu, and Riri, but in a surprising twist we neither see nor hear Misuzu this week, and Yuyu is simply fine now, thanks to Riri. They descend down to the ocean floor and together they thrust Misuzu’s Dainsleif into the Huge.
This injects it with “bug” code courtesy of Moyu, and the Huge is obliterated without a fight. Riri pulls on Yuyu’s tie, which generates a spherical floatation device. Riri briefly loses consciousness and meets Yuri in a dream, who says a proper goodbye and promises she’ll get her and Yuyu home safe.
Riri wakes up to find she and Yuyu are inside the bubble in their skivvies. They wash up on the shore, and Kaede bursts the bubble and is mortified by the “lascivious” scene. Their Legion, along with Alfhiem and many other Lilies welcome the conquering heroines home. A photo of the scantily clad couple makes it in the paper, along with the news that Moyu and Gropi finally became Schutzengel and Schild—which is staged like a wedding.
Then everyone gathers under the old tree for a well-deserved nap. This finale wasn’t all that concerned with delving back into Yuyu’s complex relationship with Misuzu or the larger ramifications of synthetic Lilies or even the role of Lilies in a post-Huge era. Instead, it gave us one last slick battle, a final boss fight that’s more of a formality, and a return to the carefree life of leisure and fellowship the Lilies enjoyed when not dealing with crises. It’s a perfectly serviceable ending.