Hoist by His Own Petard/Fan Works


 * One Star Trek: The Next Generation Fan Fic involving Q creating a second Jean-Luc seems to be written just to conclude with Data telling him "I'd say you were hoist by your own Picard."
 * In The Last Spartan, Garrus kills Dr. Saleon
 * In the Magical Girl Lyrical Nanoha fanfic Infinity, Lindy spends most of chapter 25 getting smacked around by Precia. Near the end, she reveals that she's been sealing Precia's magic the whole time, and electrocutes her with all the magic Precia used during the fight.
 * Around the climax of My Little Avengers, this happens twice. First, when it appears as though the villains have won, Trixie attempts to betray Loki, only for him to turn her own magic back on her.  Later, during Loki and Thor's Final Battle,.
 * In Winter War, the Barragan Fragment's power to age things to dust extends to its blood. The fight is going badly when Isane guesses that it might be vulnerable to its own power.