Sacrificial Lion/Playing With

Basic Trope: Character is set up as important, then killed partway through the story to show Anyone Can Die.
 * Straight: In the Dark Fantasy manga Songs of Troperia, the kid Bob is a member of Band of the Falcon, led by the charismatic Lady Alice Flameheart. Later in the story, Lady Alice Flameheart is slaughtered by Sorceror Izzard Vayne. Things are about to get serious.
 * Exaggerated: Izzard Vayne slaughters the entire Band of the Falcon save for Bob, who is Not Worth Killing at that time.
 * Justified: Lady Alice Flameheart has some sort of Thanatos Gambit going on.
 * Alternatively: Sorcerer Izzard Vayne sees how important Lady Alice Flameheart is to the group, and so deliberately kills her to strike a blow against the group's stability.
 * Inverted: Bob's final battle versus Emperor Izzard Vayne has him summoning the soul of the deceased members of Band of the Falcon, who are now Einherjar. Curb Stomp Battle ensues.
 * Subverted: Lady Alice comes back.
 * Double Subverted: ...for a while anyway. She is slowly dying from the inside, and her last moment is an epic duel versus Izzard Vayne, at which point she's Killed Off for Real.
 * Parodied: Lady Alice gets herself killed Once Per Episode to give Band of the Falcon a shot of Unstoppable Rage.
 * Deconstructed: The Sacrificial Lion is, duh, someone really important for La Résistance. His/her death severely impairs the rebellion as a whole.
 * Reconstructed: the death of the Sacrificial Lion fuels the drives of the other members of La Résistance, who fight valiently to compensate for their loss.
 * Zig Zagged: Some of the more prominent (and dead) members in the Band of the Falcon has the Sacrificial Lion trope dropped at them, while the others are essentially Forgotten Fallen Friend.
 * Averted: The only characters to die are Sacrificial Lambs and Red Shirts.
 * Enforced: "Death Is Dramatic, even more so when it happens to someone who seems invincible and is on the hero's side. Let's kill Alice."
 * Lampshaded: "Lady Alice, your death shall not be in vain! Your ideals we shall carry!"
 * Invoked: Lady Alice, having studied psychological warfare, decides to fight Izzard Vayne even though she can't win -- because she knows that her death is exactly what will motivate the Falcons for the rest of their lives.
 * Exploited: Lady Alice knows that someone is likely to die in the upcoming battle with Izzard Vayne. She plans things ahead of times so that she's the most likely casualty.
 * Defied: Bob push Lady Alice aside as Izzard Vayne throws a huge fireball at her. Amazingly, both of them survive and the rest of the Falcons finish the stunned Izzard Vayne. Lady Alice falls in love with Bob.
 * Discussed: "Oh Crap. This is where someone important dies, isn't it?"
 * Conversed: "Uh-oh, the story's getting more intense; it's usually around now the writers kill off a well-developed character just to prove that Anyone Can Die."

Back to Sacrificial Lion. Just don't get too attached.