In the Nod campaign, Umagon's first appearance has her Neck Snap a Nod Mook. She later kills 2 more when she escapes from Nod custody. Ironically, she doesn't kill anyone in the GDI campaign cutscenes.
In the GDI campaign finale, despite being weakened by a Tiberium serum, she manages to throw off Kane's chokehold on her, allowing Mack the chance to attack Kane.
Kane returns just as badass. Even if you know it's coming, it'll give you chills every single time.
Slavik:(holds a knife to Hassan's throat) In the name of Kane!
Crowd: Kane lives in death!
Slavik:In the name of Kane!!
Crowd: Kane lives in death!
Slavik:IN THE NAME OF KANE!!!
Kane:(appears on a giant screen behind Slavik) Kane LIVES! (crowd cheers) Rule of thumb, Hassan: You can't kill the Messiah.(Slavik slits Hassan's throat)
The beginning of GDI's first mission shows GDI soldiers running in terror from Nod cyborgs screaming for reinforcements. Reinforcements who proceed to rain from the sky in drop pods, blasting the cyborgs to pieces and landing on their corpses.
After completing "Destroy Vega's Base" in the GDI campaign, General Failure Vega desperately calls Kane and begs him for reinforcements. In Kane's response, he almost jokingly suggests that he could learn some things from Michael McNeil that he can carry with him for the rest of his life (which — by the way — is about seven minutes.) Vega can only ponder in horror and disbelief that Kane is punishing him by dropping a nuke right on top of him, though this may have served mainly as a way to prevent GDI from capturing intel from Vega's base.
And the last GDI cut scene has the player character, Michael McNeil, going hand-to-hand with Kane himself in Nod's Pyramid Temple. They struggle, go off-camera, shots are fired, and Kane walks back into frame, still spouting his "I'm a close second to God" gibberish, leaving the player to think McNeil is dead. Then Kane chokes, checks himself, and realizes he's bleeding, turning just in time to see McNeil running up to stab him with a giant shard of Tiberium and send him to hell with a pithy one-liner.
Kane: "I am the future! The Tiberian Sun has risen-!" (holds hands to chest, sees blood on fingers. Turns to see-)
McNeil: "NOT ON MY WORLD!" (Stabs Kane. You see the Tiberium spike jutting out of Kane's back. McNeil twists the spike and Kane falls to the floor, quite dead.) "And that's an order."
The opening Nod cutscene has a nice bit:
CABAL: A division of Hassan's Elite Guard is closing on our position. The probability of a favorable outcome can be increased if we can return to your main base and engage the enemy as we move. Slavik: Define 'favorable outcome', CABAL. CABAL: They all die. Slavik:(entirely matter-of-fact) That'll do. Let's go, no man or structure stays standing.
The GDI opening cut scene with McNeil (Michael Biehn) being commanded by Solomon (James Earl Jones), aka Kyle Reese and Darth Vader. After Kane's appearance Solomon offers the best GDI jump jet soldiers to retake a base, already being dispatched from the Philadelphia space station as the Kodiak cuts a path across the atmosphere.
McNeil: Let's kick some ass.
The Enemy Mine between GDI and Nod to take down CABAL.
CABAL gets a good one. In the Nod campaign, when you're trying to take CABAL's core offline it turns out the core is just a hologram, and CABAL starts launching waves of cluster missiles all over the map. The kicker: CABAL then taunts you with this line, "By the way, missile launch detected."