Hi Ryco! Ah yes (SPOILER WARNING), this guy looks like he teleports, but that only happens when he appears/disappears. He actually still plays completely fair! As in, he still needs to walk physically to reach a spot :).
An invisible enemy is actually quite smart to be honest! It caught me off guard which is a good sign! :)
Although I don't know if this was meant to happen but one time got caught by him instantly after I entered a door, still invisible even if you peeked. Maybe a bug?