Priori Incantatem
Reasoning: Judgment can be interpreted in several ways: as the name implies, it can mean reaping what you sow, condemnation and owning up to your sins. But it can also mean absolution, having those sins washed away, and feeling reborn.
Priori Incantatem draws out Voldemort's most recent victims, including Harry's parents and Cedric Diggory. As they descend upon the scene, they instill both terror in Voldemort and hope in Harry. The confrontation between Voldemort and his victims (Voldemort's sins revisiting him...) allows Harry to escape as well as granting him a powerful moment with his late parents and classmate.
In a traditional tarot deck, this is Judgement.
Notes
This was a crazy card to draw. CRAZY. I've always wanted Prior Incantatem for the Judgment card, but just didn't know how to accomplish it within the template. I tried showing Harry and Voldemort's wands connected, but it just didn't really work in a vertical format. I tried just showing the outer dome of light with Death Eaters scurrying around it, but that just didn't do it for me. I wanted to show what made that scene so powerful, and who actually does the 'judging': the returning shadows of Voldemort's last victims.
Originally I tried to put in Bertha Jorkins and Frank Bryce, to the very sides, but it just felt too crowded. So I cut it back to the people that were most important to Harry.
For some reason, I pictured them pupil-less in the drawing, even though that's not really how I see it when I read the book. Whatever. I tried that, but it looked a little creepier than I intended (though I did want it a little creepy), so I gave them faint outlines of pupils to compromise, and I like how it turned out. The figures themselves went fairly smoothly, but that background nearly killed me (and it DID kill my blue pen).