Minecraft One-Hit-Kill

Falling in lava, or being with diamond armor and falling from 4 blocks tall.

It doesn't matter. You'll die.
A simple datapack for Minecraft (1.13 - 1.15.2) that kills a player when taking damage.

If you're bored of it, type /datapack disable "file/ohk.zip" in the chat.

There's nothing else to say.