Ixion could have happened upon Gaath's trail before, sure. "How much of Gaath's movements" you can use, though... that would depend on how recent Ixion's observations would be. Obviously an isolated case would just give Gaath's location at around the time Ixion found the leavings... but what do you mean? Most recently (over the past week or two) Gaath has been moving through Etlon into Pelgaid, along a course giving a wide berth to the east of Pelgaid City, and through Pelgaid into Zerul.
If Ixion is supposed to have found the scene of Gaath doing something from before that, I'll need a time so that I can trace back where he would have been then... and so I can trace back which abilities he would have had at that point. Gaath is only fifteen years old, though (but was born adult), so it can't be longer ago than that.