Disable all perks, skills, and any damage modifiers, turn off all mods, potions are vanilla even if they make higher ones. Basically, a situation where it's a tooth and nail fight. Or, you can make it so they have to use the vanilla weapons/armor/potions and not their own? No enchants, just a plain vanilla weapon and armor. No upgrades. Increase all monster difficulty. Scaled-level monsters. Either way, I'll be using this when it comes out. Now, I'm a stupid idiot so I don't know much, just wanted to share opinion.