Design a Potion

[Vlaid]

Gutrot - Canon alchoholic drink drank by dwarven battleragers before, during, and after battle that is rumored to be more poison than drink.

A potion which gives the wearer a short term buff. Each round/turn a poison save is made (alchohol). Each time the save is passed, the buff increases in potency, but so too does the DC of the poison check against the alchohol . However, once the save is failed, the PC is knocked down for twice the duration that the buff lasted(passed out/sick/ect).  Make the buff some slight str/con buff, maybe some minor regen, whatever fits flavorfully with the concept. Extremely addictive. Addiction can be satisfied with alchohol.

[Vlaid]

Potion of Greater Distraction

When drank, 1d4+x number of exact clones of yourself appear. The duplicates are exact copies of the user save one. They can not speak, communicate, read or understand instructions of any kind. For the duration of the potion they will all run around, flailing limbs wildly, hooting, howling and hollering until subdued/slain (which makes them dissipate into nothing, leaving nothing behind), or until the duration ends. A spot check against the users bluff skill can determine the real one, modified by the number of duplicates created.

Potion of Minor Distraction

Same as above, except only one duplicate appears.

[Heralight]

Potion of Heavens

"These rare and beautiful bottles are rumoured to hold the direct favour of the gods. It is said that if in your hour of need, you beg the heavens to aid you, and drain the amber liquid greater protection shall never be given.

Warned also, that many after being blessed so directly, are brought to their knees in awe and shock, their mortal bodies not ready to comprehend the heavens above."

Once drank drinker is granted Greater Sanctuary, though when it fades, drinker is blind/deafend and knocked down for two minutes.

[Egon the Monkey]

Potion of The Bat
"This potion boosts the drinker's hearing to unnatural sharpness, even as it dims the eyes."
Automatically hear any stealthed PCs in a 2 meter radius for 3 rounds. Blind for 5 rounds.

This would reveal the presence of hidden creatures with otherwise untouchable stealth scores if they're foolish enough to stand too close, but leave you unable to fight them effectively until the potion wore off.

Potion Of the Earth
"This muddy brew is a link to the Elemental Plane of Earth, channeling its power through the user's spells"
10% Electrical Vulnerability, gain the Elemental Bond: Earth Perk's effects for 2 minutes.

Would exist in four forms. The others would be 10% Fire Vulnerability, gain the Elemental Bond: Water perk and so on.

[CryptWarden]

Brew Of Undeath
 

It is said that warriors ancient and new sometimes sought the beneficial qualities of undeath without resorting to the state themselves, and the necromancers who they hired worked tirelessly to bring this about.
 
They were partially successful- but it had a serious draw back. This draught was temporary, and its effects forever.
 
Immunity to Critical Hits, Sneak Attack, Mind Effects, poison, disease, and neg energy for an entire reset.
 
-4 constitution, -2 strength, -4 charisma for the rest of the character's career.
 
Possibility of being killed by other PCs for using this unholy exilir.

[Decimate_The_Weak]

Vial of Concentration:

A small vial with a black goo contained within it. It's said that these vials, though rare, are used by master's of all professions to help focus on their most precious work.

Effect: +10 concentration / 5 turns.

~

Potion of the All-Seeing:

A heavenly concoction favored by the faithful of Savras. It's said that these potions will aid the drinker in seeing the truth in everyone... even himself.

Effect: Glowing eye effect / 5 turns, +5 spot / 5 turns, detect evil/good (on use only), -1 universal saves / 5 turns.

[adharmas]

Oil of Ascension
This sweet-smelling potion was used in strange "Ascension rituals" by new religious movements to bring a swift death to people who had lost all other hope. On the label is a faded smiling red skull. Time in the bottle appears to have weakened the toxic effects.

Effects: true seeing, 1d4 wisdom & 1d4 constitution drain (no save), after 1 minute 1d4 wisdom & 1d4 constitution drain (no save)

Edit: ooh. The ability drain could keep happening for a random number of minutes (e.g. d4+1) to represent the unstable toxicity.

[Sternhund]

Thanks for the brainstorming. I just finished scripting in some ideas here and some ideas of mine.