To save Yoshino, Shido crosses a five meter barrier that would likely have killed him despite his Healing Factor. He survives.
Efreetcurbstomping Kurumi, who had earlier taken down Mana, Tohka and Origami with ease. You don't usually see a Time Master get defeated this easily.
KyouheiKannazuki successfully defending the Fraxinus from the Arbatel's attacks using the ship's Realizers with pinpoint defences, and getting in a sneak attack with a Realizer while already controlling 7 Realizers' worth of generated mana, certainly counts. That's right, he was controlling 8 Realizers with pinpoint accuracy, where most people can only do 1. And he made the whole thing look easy! No wonder he's the vice-commander of the Fraxinus. If not for his masochistic tendencies, he could've easily become the commander instead of Kotori.
After resolving their conflict, Kaguya and Yuzuru are interrupted by the Arbatel's attempt to crash into the island. Needless to say, the Yamai twins are ticked off by such a Moment Killer, so they decide to wreck the ship, as well as their army of Bandersnatch drones, with the might of their combined attack and their Angel's true form, Raphael El Kanaph.
Origami in the WhiteLicorice unit that Jessica had previously brushed off as a defective unit and delivering a serious asskicking against the incoming DEM Adeptus Wizards. Even though she ended up becoming powerless when White Licorice approaches its operation limit anyways, it shows her badassery after all her losing streaks against the Spirits.
Origami gets one by comparison. When Jessica makes an appearance piloting Scarlet Licorice, she is said to be completely crazed due to chanelling too much magic through her brain. Origami was capable of using White Licorice without succumbing to such effects.
Shido protecting Miku from Dark Tohka when Miku's spiritual energy runs out and she can't defend herself. Also counts as Heartwarming since earlier on, he had promised to risk his life to protect her if she were ever in danger, and she didn't believe him, having lost trust in humanity, especially guys, long ago.