Yeah, true!
But still in english, dattebayo doesn't mean "believe it".
It's more like something that indicates that he is shouting or meaning that what he's saying is true.
But I guess they had to find a WORD for it.... stupid ass translators....
They're probably just translating right from a book, lol.
Ok, maybe not, but at least when they translate it, they should try to make it a little more...
english like... they should know that hearing "believe it" like 10 times in every episode get's annoying.
Seriously, did they NEVER think of that? Lol