In Heroes Die, Caine's Slow Walk onto the arena sand to confront Ma'elkoth and rescue Pallas Ril (a.k.a. his wife Shanna), which results in an epic battle, the brutal killing of Berne, Caine taking a sword through the gut, and Pallas Ril Taking A Level InGoddess. It ends with the traitor Lamorak getting his head cut off by his own sword and punted into the hands of Ma'elkoth, who inadvertently reveals the conspiracy to betray Shanna in the first place, ultimately vindicating Caine and ruining his treacherous boss's career.
In Blade of Tyshalle, there's any number of great moments, like Caine laying down the three Rules for the other prisoners in the Pit. And then demonstrates on a thug named Adder what happens when people break "Rule One."
The entire escape from the Shaft and conquest of the Donjon is an extended Moment of Awesome for Caine. "They'd told you I'd die down there! I told you I'd be back! What's Rule Two?"
Deliann's speech to the Folk about trying to resist the Blind God.
Caine's strategy for getting himself and Tan'elkoth out of a burning multi-story apartment: "You ever hear of a guy who called himself Batman?"
Given how awfully the protagonists and their families are treated in Blade of Tyshalle, it's only fair that he gives them all a fair number of Moments of Awesome to make up for it. Just for Hari/Caine: beating the waterfront simulation, saving Kris in the washroom fight, Caine's whole career, outmaneuvering the attempt to infect Overworld with HRVP (shared with Shanna/Pallas Ril), taking over the Donjon from the gangs despite being a cripple, maneuvering his way into the Pit, overcoming a guard and his handicap to escape from the Pit, taking over the Donjon despite being a cripple again (and from the armed guards this time), beating two gods in a Sword Fight (again with Shanna/Pallas Ril helping), and blowing up his old boss as payback for betrayal.
Orbek Black Knife. His most iconic Moment of Awesome would be that moment in the fight for the Donjon:
The opening to Caine Black Knife, where he makes short work of Kopav Dust Mirror's ambush and delivers the clear message that the Black Knives are back.
Later, in the same novel, when confronted by Caine in the Khryllian prison, he responds with scorn to the possibility of his death in trial by combat. When Caine tries to make him back down by pulling rank as the kwatcharr of the Black Knives, Orbek growls at Caine, a man feared by 90% of the population on two planets, and asks him if he's lost his mind.
Two separate but very distinct moments stand out from Caine's Law:
The showdown between Angvasse and Orbek Black Knife, where Caine steals the spotlight in front of thousands of Khryllians and ogrilloi, challenging both Orbek and Lord Markham as the kwatcharr of the Black Knives and Agent of Khyrl. He then gives an epic speech, riling up the Black Knives before escaping with Angvasse.
"WHAT IS MY NAME?"
And now the roar did seem as though it might break the world.
CAINE BLACK KNIFE!
The finale. After a metaphysical chat between the main Powers and players of Overworld, Caine gives his father Duncan a chance to set the universe right. Cut to Earth, where Caine uses the power of the Blind God to wipe out his Social Police guards, deliver a cutting speech to the rulers of Earth over an illegal worldwide broadcast, and launch an invasion of Earth with the Black Knife Nation, the Ankhanan military, and an entire flock of dragons. The war ends almost as quickly as it begins, suffice to say.