Albus Dumbledore
Reasoning: This is the card of outstanding knowledge, insight and vitality. This card exudes an understanding and enlightenment above others, is confident and in good health. This card could be thought of as shining brilliantly, and as one recognized as great. While Albus Dumbledore is indeed an imperfect human, he is truly a great wizard full of power, genius and understanding of what is going on beyond any other wizard of the times. Though very old, he exudes joy and vitality until until nearly the very end. For most of his Hogwarts years Harry can turn to Dumbledore to depend on and believe in him - a shining ray of truth, knowledge and greatness.
In a traditional tarot deck, this is The Sun.
Notes
I love Dumbledore. I also love drawing him, although this particular version gave me unbelievable amounts of trouble getting the colors I wanted. But the linework was incredibly fun, particularly his twinkling eyes and wizened hands. Hopefully the colors I ended up choosing didn't turn out too patriotic-looking. :B