Lunar has quite a few plot holes in it, but instead of focusing on things like how Vane and the Grindery were somehow able to switch places in between the two games or how more than one dragon of the same color can exist at the same time if dragons reincarnate, I'm going to nominate the one character that the games hinge on:
Ghaleon.
There's just so much you never know about that guy, especially if you go by video game canon alone. He's the only one of his race in the entire game. His age is unknown but estimated to be anywhere from 40 to 1000. No one seems to know where he's originally from. He might be Mia's father. He's somehow powerful enough to enslave a dragon, one of the holy creatures of his world, by himself. He was able to come back to life 1000 years later in Lunar 2 by deceiving an evil god and his lie was somehow never detected until it was convenient. And he can attract fairies, even when he's a purpleish, 1000-year-dead zombie. How he is able to do any of this is never explained.
NOMINATION
Ghaleon.
There's just so much you never know about that guy, especially if you go by video game canon alone. He's the only one of his race in the entire game. His age is unknown but estimated to be anywhere from 40 to 1000. No one seems to know where he's originally from. He might be Mia's father. He's somehow powerful enough to enslave a dragon, one of the holy creatures of his world, by himself. He was able to come back to life 1000 years later in Lunar 2 by deceiving an evil god and his lie was somehow never detected until it was convenient. And he can attract fairies, even when he's a purpleish, 1000-year-dead zombie. How he is able to do any of this is never explained.