To make a Potion of Harming (6hp), you first need to make an awkward potion
after the awkward potion is finished put a glistering melon slice in the top slot and wait for the healing potion to finish
After the potion of healing is finished put a fermented spidereye in the top slot and wait for the potion of harming to finish
For more damage (12hp), put a piece of glowstone dust in the top slot and the potion of harming in the bottom slot
If you want to make a splash Potion out of it you simply put a piece of gunpowder in the top slot
And if the splash potion is not enough for you and you want to make a lingering potion from it, then you just put a bottle of dragon´s breath in the top slot and the splash potion in the bottom slot
