(Been sitting on a bunch of homebrew stuff, thought I'd share here. Thoughts are welcome!)

Amulet of Neversleep: (slightly cursed) At night, anyone in 50 feet of this amulet does not need to sleep. You do not suffer the effects of exhaustion for the duration. The effect lasts for five days.

If you are not taking a long rest at the end of the five days, you immediately make a constitution save. On a failure, you hit five levels of exhaustion and die. On a success, you drop to 1 HP. Does not require attunement, but it is possible to attune to it. If you do, you can choose when to activate its effects. However, you cannot end its effects once activated, and the effects work as above.