Kalin's voice

There's a pretty clear divide between the voices that are fresh in the VAs' minds and those that aren't. Leo is a pretty obvious one, as someone mentioned. It's much, much closer to the voice of Sora from Arc-V. Which makes sense, given Leo's current VA also voiced him (and much more recently). Luna is closer to her original voice, which I'd guess is due to it being close to the VA's natural voice.

Another one who kinda change is Jack Atlas' Japanese VA, it feels like for some reason they re-recorded some of his lines instead of just reusing the lines from the anime. As a result, the tone is different. For example, when he activated Powerful Rebirth. He's a bit more subdued in DL than what I remember in the anime.

Another one that changed, is Sartorius' Japanese VA. But this one is most likely intended - Konami clearly re-recorded his lines for The World to match the VA's much later role as Dio. Sartorius in DL is more "hammy" when using The World, more like Dio in JJBA anime, compared to way earlier in GX anime.
In other words, Konami knew about the whole "Dio's The World" joke regarding Sartorius' VA, and decided to make use of it.

I like how no ones talking about how leos voice has changed drastically

He is the same VA from English dubbed :)

He sounds like the Exodia Rare Hunter to me, but I'm guessing that's the same VA that does Kalin. I haven't gotten very far into 5Ds yet so I don't know how different he sounds.

what the above poster said, some actors forget exactly what their role sounds like. the most obvious to me is japanese Crowler is laying it on way too thick, he was kinda subdued in the anime.

According to the credits, he has the same VA. He's probably just out of practice like a few of the other VA's.