Doufu Mayoi 
Black Summoner: Volume 11 [EPUB ebook] 

Even after Kelvin has defeated Gustav in battle, Sera and Bell’s sisterly fight rages on. The two seem equally matched, but once they have revealed all their moves and it seems the end is in sight, an unexpected development occurs!

Not long after, Kelvin’s party arrives at the home base of the Apostles of Elearis, a place in Abyssland called the Evil Deity’s Heart. Just as Rion sets out on her own journey, she encounters Serge, the ancient Hero she once crossed swords with in Toraj!

Come along for the ride as this black-clad Grim Reaper and his friends finally bring the fight to the Apostles in the eleventh volume of this epic journey!