The Devil's scheme and his way of going about it make a lot of sense when you look at the very tarot he represents. His schemes largely rely on making deals with people and exploiting their weaknesses to serve his advantage, and his hold on people manifests via chains; the Devil Upright represents attachment, addiction, and restriction, among other things. But that's not all, because the same can be said for how one defeats him... that being by exploring and confronting the parts of you you'd rather hide from, as well as leaving the past behind so you can look to the future and better yourself- these things are represented by the Devil Reversed, which represents freeing yourself from limiting beliefs and exploring your dark thoughts. For the Apprentice and their love interest to defeat the Devil, they had to metaphorically- and, in a way, literally- turn his own schemes on their head.
