Wasu, who said he was Izu's brother, decided to sacrifice himself after he learned that in order to complete "Shining Hopper" one Humagear's data must be used and Izu was going to sacrifice herself so he volunteers himself. And the next upgrade of 01 would be "Shining Assult Hopper" so his sacrifice won't be waste soon also his death is kind of heartwarming to as Izu finally called Wasu as a big brother.