Dark Magical Girl/Playing With

Basic Trope: A Magical Girl with a Dark and Troubled Past, who starts out as an Evil Counterpart to The Hero, but usually switches sides after being taught The Power of Love, Friendship, and Acceptance after a big showdown.
 * Straight: Ichigo's Rival, serving under Queen Sangria, is Budou, an Elegant Gothic Lolita with an ice-centric repertoire and a Dark and Troubled Past, with the Queen serving as her Parental Substitute. Unfortunately for her, the Queen is also obviously a Treacherous Advisor.
 * Exaggerated: Budou's past, lovingly detailed and revealed throughout the series, is a Trauma Conga Line of abuse, angst, suffering, and misery that would take years upon years of therapy to unravel.
 * Justified:
 * Queen Sangria has taken blood collected from one of Ichigo's battles with her and used her dark magic to construct a copy of Ichigo from it, who she names Budou. Although they share similar powers, the taint of evil has twisted her into something far more sinister. After being defeated by her twin, the dark magic's hold over her is exorcised, leaving her a more complete copy willing to join Ichigo's side.
 * All of the Magical Girls are from a Always Lawful Good Race. Budou was trained to be evil, but still instinctively knows what she is not supposed to do what she is doing. When Ichigo defeats her, she offers her an opportunity to defect. She does.
 * Inverted:
 * Budou is a friendless Anti-Hero with a dark and troubled past, showing signs of deep depression, and generally not remotely acting her age. Ichigo is a naive servant of the Council Of The Sun, unaware of its true nature.
 * Alternately, the DMG defeats the light counterpart, causing her to lose her Heroic Resolve and join the villains.
 * Subverted:
 * Ringo serves Queen Sangria, but is cheery, peppy, and upbeat (though a bit worryingly obssessed with fighting...).
 * Queen Sangria genuinely cares for Budou, and because of this, Budou is completely loyal and well-adjusted.
 * Double Subverted:
 * However, this genkiness is a facade that Ringo uses to conceal all her issues; she's actually seeking either approval or death.
 * Turns out, Sangira's still willing to abandon Budou if necessary, causing her to Freak Out and turn into a standard Dark Magical Girl.
 * Parodied: Budou is an obviously blood-crazed psychopath, but after being beaten by Ichigo, she is tied up in a scene reminescent of A Clockwork Orange and brainwashed with friendship speeches until she breaks and starts espousing the power of friendship on her own.
 * Deconstructed: Budou's emotional scars run so deep that they can't be healed just by losing a fight with her rival and listening to Ichigo's claims of acceptance. Ichigo can claim to understand all she wants, it doesn't matter to Budou. She continues to antagonize Ichigo until she either overpowers and defeats her or Ichigo is forced to take her down, sending the young heroine into a Heroic BSOD afterwards.
 * Reconstructed: Budou's emotional scars aren't just healed by losing a fight but by leaving her with someone who can help while they're defeating Queen Sangria. The heroes also visit her regularly, and, by the start of the next series, she recovers.
 * Zig Zagged: Queen Sangria has two chosen champions, Budou and Ringo, whom she pits against Ichigo. Ringo gleefully lusts for battle while Budou is quiet and withdrawn, making her appear like a classic Dark Magical Girl...however, as their pasts are gradually revealed, it's Ringo who has an incredibly Dark and Troubled Past, while Budou is more of a Holier Than Thou Ice Queen. Both, however, ulimately serve as Evil Counterparts to Ichigo, providing dark reflections of her Hot Blooded and Prideful nature. Upon their defeat, Ringo switches sides while Budou simply leaves -- however, Ringo's turn is less about redemption and more about becoming a full-fledged Death Seeker as "atonement'', while Budou is tracking down one of those elusive therapists, and eventually returns to pull a Big Damn Heroes.
 * Averted:
 * There is no direct counterpart to the heroic magical girl; Queen Sangria just uses a Monster of the Week tactic.
 * Ichigo's counterpart among the villains is Tamanegi, a sadistic Dark Action Girl who's older and more experienced, and sees Ichigo as an irritating little goody-two-shoes.
 * Enforced: "The boys in merchandising want another cute girl to put on the merch. How about giving our heroine a dark counterpart, so we can just use a slightly different palette?"
 * Lampshaded:
 * "Why couldn't I be a happy girl like you, Ichigo? Why does my fate have to be so harsh?!"
 * Alternatively, "Oh, come on! She wears black, has a Dark and Troubled Past, and is abused by her master! All you have to do is beat her up and rant about friendship, and she'd Heel Face Turn in a heartbeat!"
 * Invoked: Queen Sangria intentionally sought out mentally scarred young girls that she could indoctrinate into her ranks and set against any would-be heroes.
 * Defied: After the first fight between Ichigo and Budou, Queen Sangria sees hesitation in Budou's eyes upon her return, and, refusing to take the chance that her servant could be turned against her, she obliterates her.
 * Discussed: "Sangria is just using you, Budou! You mean nothing to her! I'm going to befriend you so we can get ice cream together! Finishing Move: Sun's Fury!"
 * Conversed: ???
 * Played For Laughs: Budou is Ichigo's opposite in every way; while Ichigo is Hot Blooded, Prideful, brutally straightforward, and deliberately plays her cutesiness up to her advantage, Budou is soft-spoken, well-mannered, thoughtful, and kindly. This leads to everyone questioning why she's a loner while Ichigo has friends, much to Ichigo's displeasure.
 * Played For Drama: The constant battles push each girl, Budou and Ichigo, into an emotional crisis. When they next confront each other, they decide to join forces - to defeat Ichigo's mentor as well as Budou's master.

Let's go back to Dark Magical Girl. Don't worry! As long as we're together, there's nothing we can't do!