Insomnia (Vanilla)

Insomnia is a mechanic added in Minecraft 1.13, but Upgrade Aquatic modifies the mechanic to be more intuitive and flexible. As well as adding the Bedroll for sleeping without setting spawn and potions to change the player's level of insomnia, there is also a shadowy border which by default appears after 3 days of not sleeping (i.e., when the player is susceptible to phantom attacks), but can be configured.

Potion of Restfulness
Level 1 reduces insomnia by one day and Level 2 reduces it by two days. This effect instantly kills Phantoms.

Potion of Insomnia
Level 1 increases insomnia by one day and Level 2 increases it by two days.

Both potions can be brewed into splash and lingering potions by brewing them with Gunpowder and Dragon's Breath respectively, and can be tipped on arrows. As with other instant effects, they cannot be extended and there is no change to duration if made into Level 2.