One of my favorite aspects of writing 2p!England and 2p!Wales as cult leaders is that you never know how much magic, if any, they're using to keep people in the group. You'd think there's some elaborate mind control system with layers of coercive spells. How else would so many competent, intelligent, and strong nations get into this mess?
In reality, they use magic as little as possible, and it's never full-out mind control. It's common knowledge they have it, so they've got to subvert expectations of what others think magic looks like. Total control would have effects somewhat similar to anticholinergics like datura, henbane, scopolamine, etc. and would be pretty obvious. That's what everyone's looking out for.
Instead it's a sudden idea that feels OOC but makes total sense. An overwritten memory that feels more real than the original. Unexpected anxiety when given a choice. Suggestions become truths, and preexisting trust makes truth malleable.
It also has to be uncommon. Unpredictability prevents tolerance--if you constantly have strange things happen around certain people, they start to lose meaning. You learn to either ignore it or avoid those situations entirely. Being around Wales consistently gives you weird ideas? Unsettling and uncomfortable. Talking to Oliver always ends with your goal being drastically opposite of what you started with? No one can be that persuasive.
TL;DR: Oliver and 2p Wales are just really good at social psychology, which might as well be magic
