Kevin naturally wasn't here to seek revenge on Motan...
First of all, although he hadn't forgotten the comical thrashing he received in the grand arena at Sky Pillar Mountain, the key points in his memory always revolved around Reinforced Iron Bone's sheep and its owner with the leggy stride. As for the rest, the impression wasn't really that deep, so even if 'Mor' stood directly in front of him now, unless he was riding that gloriously sacrificed Self-Destruct sheep, Kevin might not be able to recognize him.
Secondly, even if Kevin did remember what the leggy Half Dragon Knight looked like, it wouldn't matter, because although the characters 'Mor' and 'Hei Fan' shared some resemblance, it wasn't enough for easy identification. Otherwise, Ji Xiaoge, who was quite familiar with 'Mor' in the game, would have no reason not to recognize Motan in real life, given that 'Hei Fan' and Motan are identical in appearance.