Tajadol is the only form where the chest symbols combine into a single form like that. Other combos r all different animals, but for Tajadol they combine into a phoenix
Wether this is Eiji's final form or not it's his purest form, or at least his desire's purest form. A manifestation of his anger he kept hold of lead him to run from his family and his desire to save others Tajador is the representation of the bond between Eiji and Anhk two people who have two separate ideals, where as this is Eiji in his rawest, and represents how he and Anhk are different sides of the coin (medal). It's why Eiji finishes the show as Tajador AND uses the Putotyra metals for his finisher, he throws his desire at Maki to destroy him
Thats always how I interpret it, because this song was sung by Eiji n the OOO belt announcer. It is Eiji n his desire manifested by OOO, the power he sought to save everyone