@daermadm Well at the last game, i heard it was a combination of 2e dust of disappearance, and the 9th level spell true cloak.
Dust of Disappearance (2e) - This dust looks just like dust of appearance, and it is typically stored in the same manner and quantity. All things touched by it reflect and bend light of all sorts (infrared and ultraviolet included), becoming invisible. Normal sight can’t see dusted creatures or objects, nor can they be detected by any normal detection or even magical means. Even detect invisibility spells don’t work. Dust of appearance, however, does reveal people and objects made invisible by dust of disappearance.
Invisibility bestowed by the dust lasts for 2d10 turns (1d10+10 if sprinkled carefully upon an object). Attack while thus invisible is possible, always by surprise if the opponent fails to note the invisible thing and always at an Armor Class 4 better than normal (while invisibility lasts). Unlike the invisibility spell, dust of disappearance remains effective even after an attack is made.
True Cloak - 9th level spell, as Arg once described it, is just True Seeing reversed.
With a tad of Nondetection sprinkled in:
Nondetection
(Abjuration)
Range: Touch
Components: V, S, M
Duration: 1 hr./level
Casting Time: 3
Area of Effect: 1 creature or item
Saving Throw: None
By casting this spell, the wizard makes the creature or object touched undetectable by divination spells such as clairaudience, clairvoyance, locate object, ESP, and detect spells. It also prevents location by such magical items as crystal balls and ESP medallions. It does not affect the know alignment spell or the ability of intelligent or high-level beings to detect invisible creatures. If a divination is attempted, the nondetection caster must roll a saving throw vs. spell. If this is successful, the divination fails.
The material component of the spell is a pinch of diamond dust worth 300 gp.
Anything else sprinkled in?
