Salazar Slytherin
Reasoning: Founder of the Hogwarts house of Slytherin, which welcomes the crafty and ambitious. This card strives for intellectual force and justice. Salazar had extremely strong goals and beliefs about how Hogwarts should be run, and when his lofty ideas were thwarted, overcame that obstacle by creating the Chamber of Secrets.
In a traditional tarot deck, this is the Ace of Swords.
Notes
His design was fun, only changed a bit from my old design of him. I think this is overall a great improvement from the older card, except for the snake wrapped around his arm. The old one was better. Oh well. The light/shadows here were tricky, as I'm not very good at them, but I think they turned out OK.