Helck manga volume 12 features story and art by Nanaki Nanao.

FINAL VOLUME!

Hoping to take down Helck once and for all, Mikaros casts a forbidden spell to summon an army of warriors with unimaginable strength. To protect his comrades, Helck unleashes his final power! This power doesn't come without a tremendous cost, however - he asks Vermilio to be ready to end his life with the Hero Slayer! Can Helck save the humans? Or will he die trying?