Yello, just joined. Had another account years ago but I lost the login information. So I had to remake it.
Anyway, I've been a fan of Suikoden V for going on seven years now, since it came out for the PS2 in 06. And I've put more hours of thought into the game, its story, and stuff than I have any other game I own. And something donned on me when I was contemplating a fanfic idea that was kind of a "why didn't I think of this sooner" revelation about the Sun Rune.
In normal cases, the Sun Rune corrupts the mind of its bearer, making them narcissistic and cruel, and in the past, uses of the rune had led to large amounts of destruction(take the ancient Armes empire from the visions/ruins.) And the only way to pacify the Sun Rune when it goes out of control are the Dawn and Twilight runes.
And the revelation: In order for someone to bear the Sun Rune and use it without being corrupted, they have to bear the Dawn and Twilight Runes on their body as well. The three are a set, Sun Rune fixes to the head, Dawn to the right hand, Twilight to the left, filling all of the body's rune slots.
But this would by no means be an easy task, as each rune is choosy about who they let wear them. But the Prince in the Lyon dies ending was shown with both Dawn and Twilight runes. So it's possible that the Sun Rune might find him worthy as well, him being a strong leader of men.