There's certainly nothing wrong with this. Lots of books have characters who speak in a dialect.
That said, what is your goal in doing this? If this is important to the plot -- either something about this particular style of speech or just the idea that he speaks an unusual dialect -- then go ahead.
If you're doing it to add "color", I'd be more cautious. Your dialect probably isn't too hard for readers of regular English to understand, but it will slow down comprehension, maybe occasionally cause confusion. Is it worth it? I'm not saying it isn't, just that it's something to consider. If this is a major character and a lot of dialog will be in this dialect, that would be more troublesome than if he's a minor character who just pops up now and then.
On the flip side, of course, having characters from far away places all speak exactly the same can also come across as unrealistic to the reader. I recall once seeing a British movie that had a character who was supposed to be an American, and at one point he mentions "making a trunk call to my solicitor". As an American I found this very jarring: An American would say "long distance call to my lawyer". As it turned out that was deliberate, the brilliant detective notices this and realizes the man is lying when he says he's American. (Though it had the catch that as a viewer, I wasn't sure if it was a slip-up on the part of the CHARACTER or of the WRITER.)
The novel "1984" had important plot points about the dialect spoken by the characters. The odd dialect was an important part of the story and not just a side point. Not quite the same, but the sci fi novel "Babel 17" and the recent movie "Arrival" are all about how learning the alien language forces people to think differently, because the language just naturally leads you to view reality in a different way. Those two stories are all about the language people speak.