Aether Walk is the Lvl 7 Skill of the Ghostslayer Bloodhunter and stated as follows:
Upon reaching 7th level, at the start of your turn, you can magically step into the veil between the planes as long as you aren’t incapacitated. You can move through other creatures and objects as if they were difficult terrain, as well as see and affect creatures and objects on the Ethereal Plane. You take 1d10 force damage if you end your turn inside an object.
Considering this question, would an opportunity attack even be able to hit the aether walking character he isn't on the ethereal plane, but in between?
Since to me this seems to be a hard take on letting the DM decide, how would you rule this scenario?
Best Answer
You would probably still provoke opportunity attacks
This feature is a bit vague, but mostly because of the first sentence - "you can magically step into the veil between the planes".
This is not entirely clear as to whether you are actually travelling outside the material plane entirely or still partially within the material plane and affected by it as normal.
The feature goes on to say that you can move through other objects and creatures but this still counts as difficult terrain. To me, this implies you are still affected by things on the material plane, just differently to normal.
I'll also invoke the rule of "spells - and class features - only do what they say they do". It says you can see into the Ethereal plane, but it does not say that you are unable to see normal objects or creatures or that they are unable to see or affect you.
So "normal" rules apply: You are still visible and able to be affected by objects and creatures within the material plane (with the exceptions noted in the feature) and so would still be subject to opportunity attacks.