Pandora weapon delivers fireworks, treating these huge demons like bouncy balls. He fires a rocket which blasts them all into the air, flings a spinning blade through the crowd which comes back to him, shoots them with a machine gun, fires a barrage of target seeking missiles which zip around blasting the toads, and then he opens the case and the toads are apparently destroyed completely, no sign of them afterwards.
Gilgamesh weapon makes for awesome gloves and boots. Smashing the huge monolith with a one-inch punch and performing over the top martial arts moves. Launching the pieces of stone in the air, jumping up and kicking them in midair, stacking them on top and then karate chopping the whole pile taller than himself in half, all in two jumps. When he spins in the air the stones are bouncing of him, showing off his strength even further.
Lucifer weapon is world's coolest backpack. Bonus for so pointedly belittling a god. He destroys that wall, draws lots of weapons and flings them into the wall in a heart shape, spins around in midair flinging these blades, then poses nicely with a rose in his teeth and claps, detonating the blades and blasting the wall into a heart shape, then flinging the rose into the last blade to split the heart in two. Destroys a demonic item in a theatrical and showy fashion.
Trolls demon. Pretends to be lured in, drops to the ground casually to check out the view, then dodges the toad's attack without looking, casually jumps away and lands. Demon demands to know how he knew, and he remarks: "You can hide that body, but that smell? Phew! There's no covering up!" making it angry.
This giant demon yells "Insult me one more time and I will make you suffer more than you thought possible!", roaring load enough to blow Dante's coat upwards.
Dante pushes the coat back downwards and laughs, saying "I'd actually like to see you try that!". He's literally saying that to a giant toad demon.
Trolls another demon and kicks her seeds in a way that makes them bounce around each other and various objects and ultimately all fly into her face. Teases her and allows her to bite him only to force the giant mouth open and hop out. All with no signs of being bothered.
Totals demon gang; bonus for walking into a bar full of thugs and ordering a strawberry sundae. Takes the first guy down without looking, dodges the following up attack in a spinning dodge, tanks a demon biting him and shears it in half, stabs the bartender through the door without needing to see him. Turns his back and lets the demon lunge at him only to turn and blast the demon.
Wins a superhuman motorcycle race. Completely outdoes the biker in every regard, appears ahead of him during the time when the bikes turns his head, wins the race, saves the biker from himself and wins the fight for good measure. Awesome racing, outpaces the bike with nitrous oxide, destroys a bridge to stop the demon's sound hypnosis, accelerates his bike fast enough to heat up from friction and outruns the demon. Doesn't flinch when a whirring saw blade is in front of his face, beats this demon.
Schools a mad scientist at both of his own games: fancy talk and demonic power knowledge. Steps into that scientist's own scene and takes it over, literally upstages him and uses him as a background framing piece for himself, ridicules his entire experiment and worldview, wins the fight easily, has that scientist begging him for information, and shows such contempt as to not answer his questions. Shoots this guy after destroying his research notes, then takes a box and shoots upwards to symbolise the fall of the curtain, the end of the scene.
Crowns a corporation-owning sorcerer the king of fools. Shoots him and sends him smashing through a thick stone wall.
Awesome entrance when he smashes through the glass roof, drops several metres from there onto the podium, lands smoothly, shoots a corrupt preacher in the face, and then stands up and turns to face the room with blood all over his face. The entire guard springs into action and attacks him, and he takes down the whole group of enemies in cool fashion. Blocks a slash from behind without looking and casually kicks the attacker flying, stabs a guy and spins him around, knocks the other guys over and flings the guy up to embed him in the ceiling. A guy attacks him from behind and Dante not only detects his attack coming but also strikes his swrd into the other guy's, sending him reeling away effortlessly. Tanks a kick to the face from Nero and then blocks two bullets from him, then lands on the statue, drops onto its hands and lands smoothly with his guns levelled at Nero. Whole fight scene with Nero is awesome, dodges all Nero's attacks early on, casually stands on a falling sword. Is trolling Nero the whole time. Strolls around with a sword in him, makes an awesome exit.
Ruler with a god complex and a skyscraper-sized mech doesn't get to look down at Dante, and Dante downs a large group of flying armoured enemies. Bonus for calling out Sanctus' superiority complex and his role as a corrupt preacher at once with his line "I didn't want you to get a creak in your neck from looking down at me.".
Saves Nero and returns his inheritance at the same time; Savior didn't like eating that. Dodges away from the huge hand an starts shooting midair. Shoots a bullet into the hilt of the Yamato while it is stuck in a moving target, then stacks another bullet on top of that bullet, then another on that one, then repeats the process another five times for a total of eight bullets stacked on top of each other on a sword hilt all shot from midair while the sword is stuck in a moving target. Bonus for being the cool uncle who lets his nephew finish his own battle.
Saves Trish in flashy fashion. Bonus for slashing the armour that much and not harming Trish. He catches her as she falls out, saves her, and takes her to a safe place. He jokes that he took in her outfit a little too much, then makes sure she's okay. She starts to talk about Urizen, and Dante tells her to stop. V comes running after Dante, but Dante responds by leaving Trish with V and riding away from V on his awesome new bike.
Awesome bike that turns into massive chainsaw blades. Awesome fight scene and bike skills.
Runs down a building on fire while carving up bat demons. Throws his sword down then runs to catch up to it.
Nevan guitar solo. Bonus for not falling for Nevan's seduction, another bonus for getting her to agree to help.
Dance moves; a tribute to a king. Nice hat and special effects. Receives enthusiastic applause and cheering from a cute bespectacled girl.
Confronts the demon god who destroyed his family. This guy destroyed Dante's brother and also killed Dante's mother, and now mocks him with a demon that looks like that mother, who the bad guy also just killed.
Makes another demon god look like a chump. Their swords slam into each other and Dante vanishes, then reapprears beside the demon with his gun pointed at his face. Charges up and blasts this demon, casually turning him to nothingness. World ending threat, and Dante doesn't even bother remembering his name.
New form and weapon, the power boost that wins the day. He stabs a sword into himself and is fine, casually references other stab wounds in the past. Absorbs both that sword and the one on his back, two legendary swords combined into one and absorbed inside himself to form a legendary new sword and form. His departure kicks up a burst of wind through the whole house. Gets between Nero and Urizen. His new sword appears, the Devil Sword Dante, and it opens up to reveal a core like lava, and summons a set of magic blades in the air around him, forming a formation around him in his new Sin Devil form. That demon is powerful enough to stomp gods and then some, and Dante is now stronger than him.
Dante slices the die. I believe this is worth several points. First, slicing a huge block of metal in half. Second, that die and game piece modelled after him control the fate of anyone in the room, and he said no to that. Third, everyone hated that dice game with a passion, literally one of the worst parts of DMC4, so Dante not only expressed what every player wanted and probably tried to do to that die, he also skipped the most hated thing in the game by doing it.
Casually catches Lady falling from the sky, saving her life. He quips about it in a way that flirts and trivializes at the same time, doesn't react when guns are pointed at his face point blank, tanks a bullet to the head, gets annoyed about it in a way that further trivializes the event, catches the next bullet in his teeth, and finally walks away casually picking the first bullet out of his forehead. Dismissively tells her to do as she pleases, further trivializing her attacks and the whole affair, and his remarks about bad luck with women while picking a bullet out of his head further proves just how meaningless the bullets were to him.
Also
Strolls into a town with an entrenched crime establishment and casually overturns their power structure, these groups included some of the most evil types of organisations imaginable, they tried to pay him off and he spat in their faces, whole gangs were squashed once they challenged him, he did so well that lots of other mercenaries and the like started following his lead, and eventually the top criminal took it upon himself to take out Dante personally. Spoiler: Dante kicked his butt.
Shrugs off bullets, trolls the big bad guy, shrugs off a shot to the head, and ultimately wins, taking down the big criminal.
Dante's awesome huge sword, summoned from nothing, his transformed awesome state, and summoning a whole bunch of swords in a threatening formation, before beating a demon king stronger than literal gods. Bonus for standing right between that demon and his nephew until Nero is carried away, and another bonus for casually snapping tendrils that were about to be used to capture Nero. Goes on to win the fight and send this demon god packing.
This post has been updated, Hecky, so you'll have to read all of it. Sorry about that.