Astral Gin

Every so often a tavern keeper will find in their bar a curious purple bottle, labeled "Astral Gin" in a silver script upon a sea of stars.  No one ever quite knows how it got there.  No one knows where it comes from: some think it made by a mad (or alcoholic) mage, some think it a drink of the Gith, others the work of a trickster god.  Regardless of it's origin, "Astral Gin" has a beloved cult (literal and figurative) following.  It is an exceptionally smooth, juniper forward, gin.  With some curious additional effects.

DC starts at 10, and increases by 2 on a success, by 5 on a failure.  It is the same DC for all checks and saves.  For each shot (1.5oz) drunk, roll a CON save.  On the first CON failure, roll a WIS save.  If the WIS save also fails, a random hallucination (GM decides) will appear.  This effect is visible to all, not just the drinker, though it will be drawn from their memories and experiences; the effect is the same as a casting of Major Image, and lasts for 10 minutes. 

On the second CON failure, the drinker, and anything they are holding, is banished to the Astral Plane for 1 minute.  This effect is very similar to casting Banishment, but not exactly the same; creatures that are native to the Astral Plane will remain there, but all others will return to the plane they took a drink on, regardless of their home plane.  Once this effect is triggered, it will occur on each subsequent shot the drinker takes, until they complete a short or long rest.  Or pass out drunk.

Each bottle of "Astral Gin" is tied to a different, but specific, point in the Astral Sea.  If a bottle changes hands, a drinker may find things that have been left behind by those who have drunk before, at the GM's discretion.

Astral Gin always comes in a a 750ml bottle.  A full bottle has 17 shots, but bottles are rarely found full.  Upon acquiring a bottle, roll 4d4 to determine how many shots are left.  Casting detect magic on the gin will return illusion and abjuration as the schools.