General Info

This mod adds potions for the Wither, Hunger, and Levitation status effects in Minecraft, coming in its regular form along with the lingering potions, splash potions, and tipped arrows! Each potion has three variants: regular, long variant, and strong variant.
To elongate the duration of the potion, combine it with redstone, and to make it stronger, combine the elongated potion with glowstone. To convert the potions to splash potions, add gunpowder, and to convert to lingering, add dragon's breath.

Wither

Regular potion: Wither I for 16 seconds
Long variant: Wither I for 36 seconds
Strong variant: Wither II for 10 seconds

Hunger

Regular potion: Hunger I for 30 seconds
Long variant: Hunger I for 60 seconds
Strong variant: Hunger II for 22 seconds

Levitation

Regular potion: Levitation I for 16 seconds
Long variant: Levitation I for 28 seconds
Strong variant: Levitation II for 10 seconds

More Details

You can make a regular potion of wither using Withered ashes and an Awkward potion. To obtain Withered ashes, you have to kill Wither skeletons. You can make a regular potion of hunger using rotten flesh and a water bottle. And finally, you can make a regular potion of levitation using a shulker shell and a jump boost potion.

Note: This mod requires Fabric API.