Co-authored and Edited by blackjack

After her failure at the royal wedding, Chrysalis swore to return for revenge, and no one believed her. They laughed at her vows, at her anger. It was their first mistake.
Now she has returned, and she is claiming the vengeance she swore on them. Her armies are different, they've mutated, they've changed. The ponies now find themselves overwhelmed and outnumbered. Turning in desperation, they summon three heroes to help deal with the new threat, only the heroes seem a little reluctant to help.