woman

After a short chat about Dante's revenge. He seems to pick up that she's either an enemy or a demon. She outright attacks and then mocks him with:

Are you really the son of the legendary dark night, Sparda? Didn't your daddy teach you how to use a sword?

He doesn't seem surprised that she knows who he is and that she attacked him in the middle of his shop after parading into his shop on a bike. In fact, he seems happy that he's one step closer to fulfilling his revenge. Even if she wasn't an enemy, by her powers, it's clear that she's a demon. Trish, however, averts the situation by telling him that she's not an enemy. She takes off her sunglasses, and Dante is face to face with an exact likeness of his mother. She tells him that Mundus, the Lord of the Underworld, was resurrected, and has been collecting power for twenty years. Coincidentally, this was the same bastard that Sparda sealed. Dante agrees to go with Trish to Mallet Island, Mundus's fortress and the link to the Underworld. In the comic, he gives her a warning:

I'll help you, woman. But, so help me, if you cross me again ... there'll be hell to pay."

Throughout the rest of the game her meetings with Dante are sporadic. Her intent seems clear to everyone but Dante—she's definitely there to destroy him, if not that, then bring him places that he will eventually be destroyed in. In the comic, she shows up to greet him in the library, flipping her back over a table and giving him a smirk and claiming that she was looking for him to warn him about the creatures that dwell on Mallet Island. Dante seems to trust her more in the game then he does in the comic; as her face seems to grate on his nerves more.

Dante meets her again after fighting Griffon for the last time, and Mundus destroys him. He displays his own disgust for Mundus's ways, and tells Trish that he knows for sure that Mundus was the one who killed both his mother and his brother. He also, surprisingly, tells Trish a little about his mother and father. He says that his mother used to tell him that his father fought for the weak, and had a righteous heart. He swears in his father's name that he'll defeat Mundus.

The next time Dante meets Trish, it's in the bowels of the Underworld. She's sprawled over the ground, calling for his help. Without further provocation, he runs toward her and is encased in a barrier created by Nightmare. This seems to have been Trish's plan all along. She gets to her feet, and approaches the barrier even though Dante calls to her to stay back. The words out of her mouth are ones Dante does not want to hear. Here he has a woman he trusted, stepping up to him, laughing at him as he lay injured in an obvious trap.

You fool, you're so easy ... Humans ... what sweets. You should know better than to trust a stranger. Your presence has become a hindrance to my master's bloody scheme. Now die!

From there, Dante's caught. He's forced to battle Nightmare and defeat it, bringing the barrier down. The rocks above Trish topple down, and as she moves to cover herself from them, Dante runs and tackles her, rolling the two of them out of the way. Trish is absolutely stunned. After she had betrayed and backstabbed him, he still went out of his way to save her, in fact, he risked his life to do it. She asks him why he did it, and his reply is very simple: "You look like my mother." Dante admits to his flaw, and tells Trish that if he sees her again, that it won't be the same, and that he'll kill her. With that, he leaves, with the voice of Mundus telling Trish that she's failed, and that she knows the rules.

They meet again in Mundus's lair. Trish is strapped above the door, her arms in the shape of a cross, most obviously being crucified. Upon closer inspection, the cuffs that should be holding her wrists are loose. Dante is taken off guard, impaled by glowing pillars from Mundus's eye while he's threatened with Trish's impending death. Trish drops from the wall above the door, and moves to push Dante out of the way of Mundus's attack, killing her. Mundus, of course, is amused, while Dante goes into a rage, chasing Mundus in Devil Trigger form and flying after him. There are two battles with Mundus afterward before Dante goes to lay Trish to rest. He leaves the Sparda, the sword forged by his father, and the amulet around his neck, which belonged to his mother, with Trish. This is also when he gives his famous "I SHOULD HAVE BEEN THE ONE TO FILL YOUR DARK SOUL WITH LIGHT!" line, that makes me giggle each time. Erm. Anyway. Dante leaves, and guided by his mother, manages to get back up to the first few floors of the castle. He's confronted by a decaying Mundus who's still swearing to destroy him.

And then Trish appears! She draws her hands back, and tells Dante to "use her power!" throwing him her electrical energy. With one final shot from Ebony and Ivory, Mundus is annihilated, but Mallet island is still sinking into the ocean. Using a biplane that's hanging from the ceiling, Trish and Dante make their getaway, with the last wonderful words:

Trish: The sky ... so clear ... so blue.
Dante: The sky is fair. It'll always be above everyone's head no different.
Trish: Like the sky ... I feel like my heart is becoming clear.

Then, after being a puppet for so long, Trish finally finds herself free of those binds that once held her. Having no where else to go, she stays with Dante in his shop, and becomes his "sidekick" (from what she calls it). The end up hunting demons together, making a game out of things, and even Dante seems a little happier then he was before.