AnWan
Ok, I found Rachel, introduced in chap 108 , she is the Archer that was one of the most powerful in the group he joined in the pocket area realm they all got trapped in. At that time she was known to Jill, that younger sister of the brother/sister pair he travelled with and became close to(the one who had the deerlike? Monster that Ashlyn liked to feed herbs to). She popped up again in chap 404(2 years after the previous incident) when she and some dude with a large sword joined the MC hunting on the Grimm battlefield with Sophia and her sister Raina. In the chaps I skimmed so far it really didn't mention the crush but on first introduction he did find her attractive and when she popped up again he noted she was even hotter than 2 years previous.