
If you're looking for manga similar to Seven Nights (Light Novel), you might like these titles.
Takes place one month prior to the beginning of the original game. It is told mainly from Akihiko Sanada's perspective beginning with him seeing a mysterious humanoid-shaped Shadow while exploring the Tartarus together with Mitsuru Kirijo.
Taking place during the events of the main game. It is told primarily through Jin Shirato's point of view and details the daily life of the members of Strega.
Ragna the Bloodedge. That man is nicknamed Grim Reaper and possesses the power of Azure Grimoire. Yet, he awakens in an unfamiliar land and has lost both the Azure’s power and his memory. In this unknown world, he comes across Celica, a girl who is able to use healing magic, and a beastkin warrior named Mitsuyoshi. Their journey is closely related to the Black Beast, a being which drive humanity to devastation. However…
Several years after the Order of the Sword incident, Kyrie and Nero (who are living together) are approached by the weapon artist, Nico. While initially wary of her rude demeanor, Nero gradually warms up to her. However, some time later a certain demon attacks Nero. At the same time, Dante's informer Morrison introduces him to the mysterious V who has a request for him. V tells Dante that suppressing this demon is Dante's reason for fighting.
Follows Nero, a teenager possessing demonic powers who is on a mission to stop the series's main character, Dante, after he assassinates demons and the leader of the Order of the Sword.
AD 2199. The world is covered in seithr and mankind is forced to live in Hierarchical cities, ascending constructions similar to towers. The 13th Hierarchical City of Kagutsuchi has been infiltrated by a man with the most bounty in the world. He is Ragna the Bloodedge, the ‘Grim Reaper’, a man who possesses the Azure Grimoire. Thus, the wheel of fate begins to turn. “Restriction 666 released, Dimensional Interference Field deployed! BlazBlue, activate!”