Radian

"Human life is ephemeral. But its all-encompassing light can destroy anything that stands before it. What awful strength you must have to beat the four guardian dragons..."

—Radian

Radian of idleness and approval and doldrums and intoxication and lightness is the final dragon, who you can fight against in Dragon Lair Cave after beating the four elemental dragons: Earth, Fire, Water and Wind.

Radian is a two-dimensional figure, quick on his feet and tosses afflictions your way like there's no tomorrow. Not much is really known about him.