Review Detail of Bearagamo in The Emperor of Darkness (DxD)

The story is awesome good character development and the way the stkry went is fantastic however the story begins to go down once Trahexia is killed he went to shield hero and was nerfed to the point its not even funny alot of plot holes as well he went from heavenly dragon king to nerfed weak pretty mich low class devil power in the shield hero regardless of his power being locked he should still be able to steam roll through everything but the power levels r so off to make a plot