Awesome / Arcane Ascension

Sufficiently Advanced Magic

• Sera starts the book with a contract to a monster who gives her ice mana. She can't tell anyone what it is, as part of her contract is that she can't reveal it until she's strong enough to summon it directly. In the final battle, Corrin gives her enough of a boost to finally summon it... revealing it to be the God-Beast Seiryu herself. She fills the entire room she's summoned into.
  Sera: Serpent of the deepest depths,
  Mother of a thousand spawn,
  Power beyond mortal grasp,
  I call upon our bond.
  My strength to yours is nothing,
  But my soul to yours demands,
  Fulfill the oath we made as one,
  And come to my command!
  Seiryu, I summon you!

On the Shoulders of Titans

• Corrin and Patrick help stand up against Mizuchi, child of the God-Serpent, known as Hero's End, at the winter ball. Patrick even manages to deflect one of Mizuchi's attacks, making her think she's genuinely facing Dawnbringer.
• When Mizuchi first shows up, one of the teachers refers to her as "young lady" before she reveals her identity. After all the fighting has gone on for a while and Mizuchi has killed most of them, someone else calls her "young lady," and Mizuchi scoffs... until she sees that it's Professor Vellum. Mizuchi freaks out, tries to fight Vellum, and gets banished by a rune circle.

The Torch That Ignites the Stars

• In the Tiger Spire, the team finds themselves in a historical scenario taking place shortly after the war that made the Cadence family famous. Corrin gets challenged by a man who he knows from history, a famous duelist with a personal grudge against his family. The man is powerful, experienced, and specialized for dueling. Corrin stomps him so hard he looks like a child.

The Silence of Unworthy Gods

• The duel between Corrin and his father, Magnus Cadence. This has been building up the entire series, ever since Magnus disparaged Corrin's attunement. It starts with some careful bluffing on Corrin's part where Corrin has to look like a coward while trying to look brave, resulting in Magnus declaring that it will be a no-holds-barred duel to incapacitation or surrender. Corrin convinces him to start with a handshake (one of the traditional ways to start a duel), which Magnus deduces is because he's slightly less ridiculously overpowered in close combat. Except the second they shake hands, Magnus realizes something is wrong. Corrin just stands there, unconcerned, as Magnus tries and fails to use his attunement on him. At first he assumes it's Corrin's Anti-Magic sword; Corrin tosses it away to no effect. Magnus realizes that Corrin must have used his Arbiter mark to steal his attunement, but Corrin didn't do that either. He could have stolen it, or destroyed it, or sealed it away forever. Instead he changed it, swapping all the data in the mark for the one in his own—making Magnus a Citrine-level Enchanter. In theory, he's as powerful as he was before, and if he had a tenth of Corrin's skill, he would have killed him already. But he had spent his entire life relying on his Shaper attunement while disparaging Enchanters; it's likely he doesn't know a single rune. As Corrin notes, if he had crippled him, Magnus could have claimed his training made Corrin ruthless enough to win. But this way he is rendered completely helpless because of his own flaws. Magnus is left on the ground, weeping.
  Corrin: Father's mistake was that he'd seen the duel as starting the moment he'd challenged me. In truth, it had started the day I'd earned my attunement.