Shaman King: Marcos - Chapter 4
You can support this series by purchasing the complete volume, which are currently available in Japan but may be available in multiple languages from around the world soon.
Shaman King: Marcos is also currently running in "Shonen Magazine Edge" magazine. This magazine can also be purchased digitally every month around the 17th.
The events in Shaman King Red Crimson take place prior to this story. You can also support this series by purchasing this manga as well.