Hey there! Mort's more of a general practitioner than anything at this point AKA I haven't thought of a specialization yet, but he definitely could have seen Riku in the past!

He writes cheesy self-help books about managing one's desires, since desire was a HUGE theme in his canon. XD I wound up making up titles for three: Desire, Doubt, and You; Purpose through Passion: A Guide to Finding What You Really Want out of Life; and When Desire Attacks: Balancing What You Want Versus What You Need.