"Asta will need to get much more powerful if he ever hopes to defeat the demonic leaders of the Spade Kingdom. Things look bleak, but then a mysterious mage named Nacht appears--and he knows a few things about harnessing a devil's power. Does Asta have what it takes to learn how to control his own devil powers and rescue Captain Yami?"--Back cover.
"Having finally mastered Devil Union, Asta must head to the Spade Kingdom to help his friends. But he's gonna need some help getting there. And will he be ready for the devilish terrors that await him?"--Back cover.