I have played Gnar a few times, and found that his Q return can be kinda weird. It will sometimes fly in the general direction that you are moving, but really far ahead of you. I don't know if this is just me stopping occasionally while moving to auto or it is actually an issue with the tracking.
PhailRaptor5 votesIt seems to use the same general logic that Draven's axes do. If you are moving, it will set a path that assumes you keep moving. If you are not moving, it will put the return path directly back through the spot where you threw it from. If you start moving a second or so after throwing it, it will be on your path of travel sort of close by.
And, just like Draven's Axes, it will occasionally produce unreasonable results.
Worgslarg1 votesIf you are moving when you cast it, it will go to where it would hit you assuming you kept moving.
Personally, the indicator for where it will return should be visible as soon as you throw it.
Willahelm Fulber2 votesThe indicator should depend on WHEN it calculates where the q will land; if it calculates when you throw it then it would always come straight back as if you were stationary. I think it calculates upon hitting the first target (beginning to slow down and reverse).
