This is may be the hardest mod that exists or ever has existed.
Features include:
Gives you Perminent blindness, mining fatigue, unluck, weakness and slowness.
Regulerly sets your health and food to 1.
Perminatly puts a carved pumkin on your head.
Makes all mobs exept for enderman, blazes and the ender dragon Invulnerable.
Kills you if a mob hits you or if you hit a mob.
50% chance of teleporting you to spawn when you jump.
Blows up tamed mobs.
Adds Sentrys that shoot you rapidly
Adds Sentinals that rush you and blow through walls.
Gives you levitation when you enter the end.
Adds obsidian crystal structures with end crystals that heal the dragon.
You can use this mod in your modpack.