Ruined Dragon

The Ruined Dragon, also known as the Lord of Lightning , is a giant dark purple dragon encountered in the Ruined Kingdom in Super Mario Odyssey. According to Crumbleden's brochure, it is thought that the altar with the shape of his head in said location was built to talk to him or possibly confront him, with it being made to restrain the lightning. It is also implied that he is the one responsible for reducing Crumbleden to ruins. His Japanese name, "Crumbleden Dragon", indicates that the "Ruined" term in his name refers to the place he lives in rather than his physical condition.

When first meeting him, the Ruined Dragon is seen wearing a golden crown featuring the shape of Bowser's head on it, as well as various horns and a black cloth with golden motifs similar to the ones seen in Bowser's Kingdom. After being defeated, the Ruined Dragon no longer wears said crown.

Unlike other bosses, he does not explode after being defeated and instead rests hanging on the tower of Crumbleden. If Mario gets on the plaza on top of it, he follows Mario with his eyes and closes them if Mario throws Cappy at them, and can even be talked to. After activating the Moon Rock, a Power Moon can also be obtained by throwing Cappy at the tip of his upper right horn.

Compared to other dragons (and most creatures in general) in the Mario franchise, the Ruined Dragon has a more "realistic" design, with detailed textures and little cartoonish exaggeration.

Battle
The Ruined Dragon uses two types of attacks: the first one are magenta lightning bolts from his mouth that hits the ground in front of him, generating various rotating spiked wheels made of electricity that are able to slightly change direction to chase Mario. The more the Ruined Dragon is hit, the more spiked wheels are generated through this method. The second consists in electrifying his head and slamming the ground with it, generating various magenta electrical streams that diffuse in all direction and have to be avoided. Like in the case of the spiked wheels, the more the dragon is hit, the denser the streams are and thus the greater is their coverage of the surrounding area. A few seconds after the second attack, the head stops being electrified and the dragon is forced to rest, allowing Mario to jump on his head and use Cappy to remove various sword-shaped pins on his head that keep a crown shaped after Bowser's head into place. Each time a pin is removed a creature similar to a dark violet Burrbo comes out from where the pin was stuck and tries to hit Mario with electricity. Once all pins are removed, the crown disappears and Mario is able to Ground Pound his head to hit him. Every time he's hit, the number of pins keeping the crown in place increases. Once he's hit for the third time, he faints, and leaves a Multi Moon that is needed for the Odyssey to be repaired.

The rematch in Peach's Castle is mostly the same, but the streams of electricity the dragon creates after slamming the ground with his head now appear in a vertical zigzag pattern, meaning Mario must jump over some areas and run under others. Also, the battlefield is icy, giving Mario less traction.

Quotes

 * "So...tired..." - Super Mario Odyssey