Mebius Phoenix Brave is Mebius' fusion form, attained by fusing with Ultraman Hikari as well as his friends at Crew GUYS. It was used to defeat Alien Empera in the series finale.

In Ultraman Hit Song History: New Hero Chapter, this form was achieved again sometime when Heisei Ultras had been imprisoned in Yapool's Dimension, with Ultraman Zero as a recent victim. However, with the combined effort of Zero and Mebius, they finally destroy Yapool and free the captives in said dimension. However, given that Mebius and Hikari were alone in that dimension, it is still a mystery on how did they managed to gain the combination technique despite the GUYS members were not with them. However, it is possible that they were already in that fusion before being captured (meaning that Yapool had captured them in a time travel-like ability) or Mebius and Hikari can simply concentrate their bonds to gain that power.