The Strongest Sage with the Weakest Crest manga volume 24 features story by Shinkoshoto and art by Liver Jam & Popo (Friendly Land).

After settling things with the human-demon hybrid, Matthias begins to piece together a theory about what occurred during the long years before his reincarnation in the current era. The severe regression of magic civilization and appearance of devastars seem to hint at the possibility of space monster involvement. If Matty's theory is correct, he'll need to craft a transcendent weapon to deal with the very monsters he felt underpowered to fight as Gaius!