By Raffaele Litto (raffaele@rocketmail.com)
I would suggest to make it accessible to the Tremere, Assamites, Sabbat Tzimisce and the Followers of Set.
The ritual enchants one Blood point of the subject so that, upon consuming it, the beneficiary of the spell temporarily loses memories, powers or knowledges that were imbibed in it. For each success on the ritual, one dot of a discipline, one memory or two dots from a knowledge can be hidden in the blood of the receiver. (For a guideline for how many memories can be "stored", use the table in the Forgetful Mind (Dominate) power but subtract two from the success needed: one success for slight alterations, and so on.)
This blood point should be marked differently, because, when consumed, it negates access to the chosen abilities and memories, just like they never belonged to that person. This prevents mind reading for catching stored thoughts, and diabolists from gaining knowledge or Powers from their victim, if the blood is consumed before such attempts are made. The "burned" secrets will start coming back after three days, one dot each day after the third. More than one blood point can be used to store something, but only one kind of secret (memory, knowledge or discipline) can be hidden for each use of the ritual. The obvious limit is that a vampire is limited by the amount of blood he has available. Note also that this ritual cannot hide the aura of the Cainite and that cautious scrutiny (5 successes) reveals blood red veins (similar to that of diabolists). The use of this ritual can also be perceived by the use of the Path of Blood (A Taste for Blood, needs more successes than the initial successes of the ritual)
If the subject for some reason has the enchanted blood removed from his body (via Path of Blood or Quietus, for example) he will lose access to the stored knowledge until they come back. This would be rather dangerous if it happens during combat, and you lose access to a Power you really need. Moreover, any kindred drinking the enchanted blood point before the secrets have returned to their owner will have knowledge of what was stored inside.
The uses of this should be obvious: a spy or messenger could be made to store dangerous information, or an Elder could make sure no one at the next Conclave would discover, by mind reading, his secrets. Some of the most paranoid Ancients would shield all their powers so that, in the last moments of his life, before being diablerized, he wouldn't give his destroyer all an unlife's knowledges and strengths.
Some rumors mention a stronger ritual that confers the power to store the generation recipients, allowing them to appear to be of higher generation, so as to walk undisturbed among the youngest vampires. Another rumor speaks of a ritual that bestows the stored powers to the imbiber of the enchanted blood for days, removing them from the blood owner. The thought of a neonate Sabbat wielding the power of a sixth generation Tzimisce is enough to give daymares to most Justicars.