This is one of those little badass moments that’ll pass you by, steeped as it is in so much drama.
Usagi, through desperation and force of will alone, is able to stop her attack mid-flight. Nobody else does this. Obviously we’re into pure headcanon territory here, but with every other Senshi, there’s the sense that once their attack is fired, that’s it. They may maintain some kind of control over it – form, intensity, direction – but it’s going to to obey some rules. Energy, mass, velocity, whatever sciencey laws you want to apply. If Rei flings a white hot fireball the size of her head, there’s no making it disappear at the snap of her finger. She can dissipate it or try and steer it away (maybe, depending on what kind of control you see her having), but it it’s gearing the attack down, not stopping it.
Usagi fucking STOPS IT.
A whirring disc of light and death flying at ridiculous speed that’s effortlessly cleaved monsters in two, and Usagi PULLS THAT SHIT IN. The tiara stops on a dime. It goes from “moving” to “not” like it slammed into a wall just inches from Naru. It still has to speed down its rotation and the energy fades slowly, but the control Usagi displays in that moment is sincerely impressive. It shows in a very understated way (particularly as it’s never commented on) just how much more power is in Usagi than anyone realizes, particularly Usagi herself.