User blog comment:GSFB/Perseus (2010 Movieverse) vs Avatar Aang/@comment-26074921-20120816210236

Aang will take this battle without much issue.

Aang's bending should never be underrated, especially in combat with someone like Perseus who is essentially lacking anything equivalent in power. Non-avatar state bending should be plenty to defeat Perseus, who's weapons are essentially useless against Aang who can maneuver the battle field with immense speed and agility. Most of Perseus's weapons require him to get very close to Aang, which I can't see him getting near Aang in this battle. Even if he does, I doubt he could even land a hit on Aang, or have a way with dealing with the bending at all.

With the mounts, the situation is similar- No Contest. Appa is far larger than the Pegasus. His size and girth is such that I doubt the pegasus will be able to damage Appa at all. Appa is larger, stronger, and even has his own bending to an extent.

As for the deal with Medusa's head I have my own theories on that. My idea is basically that when looking at the head, rather than turning to stone, the head will present the avatar with a danger to his life which would trigger the avatar state to protect himself. In the avatar state all the past avatars and the Avatar spirit itself would prevent Aang from turning to stone. Essentially Perseus using the head is signing his own death warrant.