Kingdom Come: Deliverance is not exactly an easy game, but you can transform Henry from lowly peasant to fearsome knight fairly quickly if you know what you're doing. Modder Knoxogoshi's Ultimate Realism Overhaul looks to change that by making the game harder, especially early on. It bumps up the difficulty of combat, slows down progression, and makes Groschen—Bohemia's currency—harder to come by. It sounds brutal, but if you've already finished your first playthrough then it might be a good excuse to start all over again.
It touches on almost every one of the game's systems. The mod tweaks every weapon's damage value and strength requirements, which will make it more difficult to wield the best weapons and almost impossible to one-shot enemies late in the game. You'll also have to pay more attention to the type of weapon you're using: maces, for example, will do barely any damage against padded armour, will weigh a lot more than other weapons, and will have a much shorter reach.
The mod shrinks the window for a perfect block, while enemies will co-ordinate their attacks to try and hit you at the same time, rather than queuing up to strike, which they tend to do in the base game.
The mod slows down leveling and nerfs some of Henry's perks. You'll build up hunger faster—to the point where you might starve if you don't eat for a day—and you can't simply eat from stew pots anymore, because they'll only give you a tiny meal.
Making money in Deliverance can be a struggle at the start but this mod makes it ever harder by lowering the prices that merchants will pay you for goods and ramping up the cost of certain items, especially armour.
It'll make the early game particularly difficult: inflated inn prices mean you might not be able to afford a room for a while, leaving you to sleep on the street. And because you'll need more food, you'll run out of gold quickly, which means you'll probably have to steal lots of bread if you want to survive.
Best of all, it's modular, so you can choose to just overhaul the combat and progression systems, or take everything but the economy changes, for example. Download it all from the mod's Nexus page. I'd recommend reading the description in full first so you know what you're getting yourself into.
If you're looking to tweak the game further, check out our list of best mods.