In which mc-san has an ability known as "gluttony" which he believes to be useless and gets bullied for it. However, he one day finds out that it may not be as useless as he believes after talking to an interesting sword that promises power if used. He finds out that "Gluttony" is a skill that sucks up the powers of the things you kill and might also give you their skills, but if you don't feed it, it will make you go insane, hence "Gluttony". Because of this, mc has to go around killing many things to keep himself "fed".
Really good premise and it's not a harem! Yay! I just hope that it's as good as I hope for it to be. This gives me serious SAO vibes with the Kirito-looking mc, and the dark vibes! This is a seinen manga, and not a shounen, so I have faith. Let's hope it holds up though.
Novel Link:
https://www.novelupdates.com/series/glutton-berserker-the-one-that-exceeds-the-concept-of-levels/
Berserk of Gluttony