He's got elite agility and very good top speed. His transition and backwards skating are areas where he could improve, but he's made some nice improvements there in the last two years.
It's tough to find a comparison among defenseman, because he's a very choppy skater, which is much more common among forwards. He's a little reminiscent of how Johnny Gaudreau skated.
He's also not the most fluid backwards skater. Mark Giordano struggled similarly, but he was obviously a lot bigger, making it easier to get away with.