@Captaininvictus
It's 暗黒兵士 – Ankoku Heishi – Dark Solder.
Also, I would suggest another interesting variant – The Black Demobee https://youtu.be/TZCZ9DWCwuI?t=3705
@Doomer, the father probably reported the case to the town's guild. And those adventurers came here and wanted to see that glorious man who killed the snake. But when they saw merely two D-rank adventurers here they thought that all of it is just rumors. And though there is totally changed...
@Fari
They actually know Bashubaza's name. But they distorted it in different ways because of their dislike to him. They were saying: Bakabakka, Bakabaza, Kasubaza, etc. It's lost in this translation.