Leech

Leech definitely abuses the fact that Delusions can cause trouble to humans with no repercussions in the cove. In fact, he had no idea that the yumenari even had that rule, much less obeyed it! He thinks they are very lame for that.

He causes the hallucinations of burning alive and includes the wounds that follow, ranging from first degree to fourth degree. The victim can smell, feel, and see their skin burn away from blue flames. The most common hallucination he causes is a third degree burn, rarely ever doing a first degree because he loves watching humans writhe in pain. Especially when he stops the hallucination and sees they are in a state of confusion when they realize their skin is perfectly healthy. Well, as healthy as it was before his interference. It's not uncommon for a phantom pain of the burning to stick around for a while.

Despite having the power to charm yumenaris to withstand the delusions' miasma, he most often does not. If he does, it's only because he took a liking to one. Which is rare, he's not a very people person. He may be extroverted but that doesn't mean he's likeable. If he were an average yumenari, he'd be a menance at best. But being almost 700 years old, he is quite adept with his magic and causes as much chaos as he wants. Which... is quite a lot.