[Katekyo Hitman Reborn!/Mammon] Mammon's Journey Through the Anime Multiverse

(P.S. I started this story a long time ago. I'm trying to fill in the hole.)

His teacher told him to get stronger, so he did. The mysteries his teacher left behind after vanishing? He solves them one by one.

But what's with these guys? Looking for a fight? (They're not.)

A kid with decent fighting skills and questionable intelligence.