[@Rune_Alchemist] I'm the one who brought up DnD actually, and is was only for an example. I think the best solution would be he just uses it, being mindful of limitations. And it can be situational based. If you disapprove of it or think it's too powerful at the moment you can ask him to edit it. Because I really think you're both on the same page for the most part but have trouble understanding that.

I'm sure once he starts using it you'll be satisfied to the level he uses it, and if not you can tell him, suggest things, work it out from there to get a better understanding. Because at the moment is it theoretical and not being but into action, per say, and I think that's where the miscommunication lies. You both have said that the character is able to manipulate thoughts, not necessarily control them fully, depending on the "intelligence" level. Although willpower of each individual may be a better solution, where maybe some may not be the "smartest" but have the "willpower" to fight it off. There would probably be an average for a certain group of monsters or race, but would vary from person to person, bosses or higher ups being less susceptible. As the character gets stronger, he can overcome creatures with a stronger willpower and influence them more, for longer, and cause different effects.

Again, just simply being a neautral party on the matter, but I believe once we actually have some IC going and the character gets put into use, I'm sure things will smooth out.