Potion of Fire Eaters[]
The Potion of Fire Eaters is a deep red potion, which inflicts the Fire Eater effect. It causes entities to NEED fire to live. If they're on fire, they gain health and are strong, but if they are not, they are quickly consumed by Fire Eaters (invisible things that don't really exist).
It can be brewed from vanilla lava and a Blazing Heart. It can be both elongated and amplified. Brewing it with glowstone produces a Potion of Fire Eaters II (double the healing power/damage). Brewing the amplified version with a Plagued/Pure Tear (a Plagued Tear, in this case) creates a Potion of Fire Eaters III, an even more extreme heal/damage.
Brewing the base Potion of Fire Eaters with redstone elongates it, making it last twice as long. Brewing THAT potion with a Pure Tear elongates it again, quadrupling the original duration.
Vanilla lava and a Blaze Heart brewing into the Potion of Fire Eaters.
Potion of Fire Eaters brewed with glowstone dust to create a Potion of Fire Eaters II.
Potion of Fire Eaters II brewed with a Plagued Tear to create Potion of Fire Eaters III.
The Potion of Fire Eaters and redstone dust brewed into the elongated Potion of Fire Eaters (double duration)
The Potion of Fire Eaters (elongated) brewed with a Pure Tear to create the Potion of Fire Eaters (quadruple duration).