I think its safe to assume there is time travel involved for both Keldor and Evil-lyn at some point in her abducted life. Personally I don't care for the technique of taking a straightforward scene and adding an Ulterior-motive layer like in Price of Deciet and Keldor's now false introduction. That's not to say its a contradiction at all, merely a minor retcon.
I suspect King Hiss got his emmissary/mysterious ally a bit like that page above. A magical stranger with power promising to help out king hiss in his battle against the ancients. Basically the unmade (and now still going to be unmade) Powers of Grayskull He-ro/Keldor story.