Beast introduces the warring Cybeasts Gregar and Falazar, as well as the Navi Trill. Pitted against the newly-emerged Zoanoroid armies of the Cybeasts, Lan, MegaMan, and a select group of their partners, find themselves drawn into the parallel world of Beyondard. Guided by a mysterious girl, Iris, they join the human resistance in the fight to claim the "Synchronizer" powers of Trill, with which MegaMan is able to "Beast Out". Nearing the end of Beast, the android brain belonging to Wily of Beyondard reveals himself along with his lackeys, Blackbeard and Yuika, hoping to acquire the victor Cybeast as his new body. Ultimately, the two merge together into the Super Cybeast Grezar, which becomes Wily's vessel with assistance from Trill's powers. MegaMan and Trill merge together and lend their strength to Lan to form a "Juuka Style," giving him the strength to destroy it.