the Jester
Legend
I think a fair number of old psionic classes would work as subclasses of other classes: the psychic warrior is a fighter with a splash of psionics a la the eldritch knight; the soulknife is easy to see as a blade pact warlord whose benefactor is some sort of psionic entity such as an elder brain; the lurk or whatever it was could be a rogue subclass; etc.
I do think a feat like the Magic Initiate feat would be a good option, too. (Wild Talent?)
I do think a feat like the Magic Initiate feat would be a good option, too. (Wild Talent?)