The Leo Vertex (レオ・バーテックス Reo Bātekkusu), also known as an Shishi Type is an enemy of humanity, and the eleventh Vertex the Hero Club encounters. It is based after the constellation Leo the Lion. It is the strongest known Vertex.
Creating a massive fireball that could be compared to the sun, and required all the Hero Club's strength in order to just stop it.
Also, at the end of Nogi Wakaba is a Hero, it was the Vertex responsible for causing the world to become its current appearance, a world of flames, by self-destructing. This also wiped out all 11 of the other evolved Vertex in the process.