Darth Thanaton vs. Thon (Force Battle)

The Dinosaur that contained the spirits in Lake Nath vs. The Lightning flying guy

Battle takes place in the Valley of the Jedi

Probably Thon. He knows anti-dark side powers like Force Light and Wall of Light, which could be of use. He probably wouldn't fall to Thanaton's mental rituals, at least, but I'm not sure if his Deflection is sufficient to repel Thanaton's Lightning Storms.