Trish driving a motorcycle through Dante's door. She then shows her skill and power by knocking him down through a combination of martial arts and lightning. Granted, Dante does recover rather quickly and turns the fight in his favor, but it's rather impressive for Trish given who she was dealing with.
The First-Episode Twist is both awesome and dramatic. The mysterious Trish removes her sunglasses and looks back at Dante, then the camera shifts to Eva's portrait, revealing that Trish looks like Dante's mother. Dante is visibly surprised at this turn of events.
Mission 2
The first cutscenes gave you a good deal to go off with. Okay, sure, this guy is a Badass Longcoat, you get it. Nigh invulnerable, uses two guns, nice... It's all very nice, seems like it is ramping up to be a cool action game. Then you see this scene. There's a point during it when you think to yourself, "No, he's not going to do that!" But he does slowly lift himself up the ground without even lifting the sword that impaled him beforehand. This was the make-or-break moment; if you weren't mesmerized by the sheer coolness of that scene, chances were, this wasn't the game for you.
Mission 3
So far, you've mostly been fighting lesser demons like possessed puppets, evil spirits and whatnot. Now it's time for the first proper boss of the game: Phantom, a spider-scorpion demon made of stone and lava, crashes through the cathedral ceiling, and he's several times bigger than Dante is. Dante's response? He treats about as seriously as every other mook he's encountered up to this point: i.e. without any respect whatsoever.
Right before the first fight against Mundus, the seriousness comes in, full stop. After about twenty levels worth of badass taunts and one liners, Trish gets to save Dante, and we get to see what he's like when he's really pissed off at Mundus. No joking, just a Berserk Button being pushed, a Sparda Devil Trigger, and a badass two-part fight following.
Devil Trigger works differently in the first phase of this fight as Dante's DT runes are fully consumed to summon a flaming dragon demon powerful enough to break through Mundus's barrier with a single tackle. This attack deals a significant damage against the boss and Dante can summon it again for as long as his DT runes are replenished.
Mission 23
Trish lending Dante her power to defeat Mundus. The player has a moment to control Dante in-game in order to fire the newly-powered Ebony & Ivory, which is followed by this exchange if you manage to pull it off.
Trish: Looks like we have a winner... Dante:Jackpot!
Miscellaneous
For the player, surviving the entirety of Dante Must Die mode would cause Dante to have some of his dialogue change during the ending sequence, along with a remixed version of the result screen theme. You're then rewarded with Super Dante - picking him on a New Game means that he has his base stats and weapons, but when you get Alastor and Ifrit, this Dante has infinite Devil Trigger!
. There's a point during it when you think to yourself, "No, he's not going to do that!" But he does slowly lift himself up the ground without even lifting the sword that impaled him beforehand. This was the make-or-break moment; if you weren't mesmerized by the sheer coolness of that scene, chances were, this wasn't the game for you.