Disastrous Dark

My third modpack, and arguably my best work, this experience is designed to make you legitimately struggle to get - and maintain - a foothold in your world. Every death moves your spawn point, every mob has the ability to invade your home, and every pitch black inch of the unlit world hides something that wants you very dead. "Epic Siege" adds mob buffs, meaning planks alone aren't enough to keep zombies and breach-happy creepers out, "General Disasters" and "Weather, Storms, and Tornadoes" both threaten to rip up your home, "Iberia" makes your spawn point move with every death, removes F3's coordinates, and makes all covered stone blocks turn 10x harder to mine, and several other mods provide their own challenges in little or big ways. If you want to really stretch your Minecraft knowledge for every advantage you can find, grab this modpack and suffer.

(The Lost Cities worldgen option is ideal. You can pick the one you think most fitting, though I suggest "Rare Cities". The wasteland city options are a true hell.)

P.S. If you find a part of the pack that isn't fun, or have an idea to improve it, please tell me in the comments.