Potion of sleepiness can be brewed by adding chorus plant onto a slow falling potion.
Effects
Potion of sleepiness lasts longer than potion of feather falling. When the player falls, at the stage when fall damage is calculated if the fall is lethal, the player gets teleported back to where the fall was initiated (the block where he was standing before or the closest to it if it was broken) and any movement controls get discarded (if the player holds w key while they fall when they get teleported they need to release & press the key again to move in said direction)
Optional
To balance gameplay a bit, the rule that the potion can only be activated on the days when phantoms can spawn can be added. But I think it would be a bit much.
This is a really cool potion effect! The way it’s made is quite unique, and the effect seems helpful.
I’d suggest having this not just apply to falling. For example, it could teleport you out of lava or the void should you fall into those. To balance this, I’d have the duration be the same as slow falling (1:30, 4:00 if extended with redstone) or maybe even less.
I also think the name should be changed. “Potion of rewinding” is a much more fitting name that does a better job of communicating the point of the effect. To be even clearer, the actual status effect could be called “Protective Teleportation”.
The optional rule doesn’t really make sense. It’d make the potion super confusing — sometimes it works, but sometimes it does nothing.