Len is a mysterious figure who is fighting Xaviax' monsters who has the ability to transform into Kamen Rider Wing Knight armed with a bat Advent Deck. He is aloof in personality and tries to keep the Riders' existence a mystery from the public. His Advent Beast is Black Wing, a bat. He is one of the original Kamen Riders from Ventara before their "betrayal" by his best friend Adam, the original Dragon Knight. At first, Len did not want Kit to get involved with his problems or become Dragon Knight. But once Kit used the Advent Deck, they agreed to defeat Xaviax and save Kit's world.