The Purge

You can physically see sickness, though not sickness of the body. Yours is the domain of the supernatural and the spiritual. Anything that doesn't belong - you can strip it, flush a system clean through and cleanse it of unnatural corruption. Your power is restricted to sentient things, but you can return the creature or person to a place of relative spiritual health, and for a moment in time remind them of what it was to be truly themselves.

Long Description: For some entities, being purged out of a body is enough to free the victim entirely, although if the parasite has a way of slinking back in - and remaining without its host indefinitely - you'd need to repeat the action. For the strongest of ill spirits your blood is needed to be consumed by the victim, enough to nearly kill you on some occasions.

You can physically see points of spiritual or supernatural sickness, as well as persistent foreign power that is active on an individual. You cannot always define what it is. It's all shades of an anomaly that doesn't belong, with the sickness appearing as a wan little shape gone wrong, often in a specific location of someone's body, sometimes in different false colours. Other times still, it's more general: a cloak of distorted ill wraps around a victim's entire form, a black haze hangs about their skull. From possessions to arcane parasites to long-standing mental suggestions like a vampire's Dominate, you have an undisputed mastery with forcing such things out - out of a person, out of an animal, out of a phylactery, or even out of your fellow human captives, should one of their powers be influencing another one of you.

Unfortunately, this tends to leave you open to the very invading force you have dispelled - because you have no such ability to purge it from yourself. Often, the very things you 'cleanse' you take on directly, to an even greater degree. Purging the Celebrant's power from someone else gives it to you at full strength and more, doubly so.

A point of philosophical debate or deeper concern: you can also purge a vampire's Beast, or at least reduce it so heavily that it feels truly absent to the vampire. It always returns in full force at dawn, leaving you to wonder if it's there all along even after you've purged it - just so tiny as to be invisible? Or does it somehow return to them by forces unknown?

For some vampires, the force of being free of their Beast for any length of time - to feel it so muted as to be absent - is a sledgehammer the likes of which has no compare. And the return from that place of peace is so ugly a contrast as to leave them in far worse a place than before. It is easy to become addicted to the sensation of self-control and freedom.

Mechanics

Frequent Use/Minor Version

You can use your minor power once per hour, on any creature; if you attempt more your body feels shaken and raw and it hurts immensely to even try to overtax yourself, to no effect. Therefore it is wise to locate the most affected or most dangerously impacted target in a room affected by something - such as a fellow human's power gone wild. The target you approach decides off-game for themselves if it purges them strongly; if it does not take as well as your character expects, you still feel as depleted and exhausted, and likely worried as to why. (That is the nature of fluctuating, poorly controlled powers.)

Purging an extreme use of any of your fellow humans' powers requires a similarly extreme use of your power too (see below); so if you've already used it up on any night you cannot purge it. A whole room affected by an extreme power is not something you can cleanse, but you could clear one person. Whether it's worth your energy is another matter entirely. Sometimes it's better to slip away.

To purge something narratively minor, place your hands on the target and verbalise clearly your intention to purge them of the supernatural ill, using the word purge somewhere in your statement. A narratively large thing to purge - especially in the case of persistent or elder Dominate - will require them to drink a lot of your blood, and is an extreme use of your power (see below).

A vampiric target must always be willing.

A human target can be unwilling.

Extreme Version

For: Powerful Dominates, Extreme Human Power, Beast Traits, and Malkavian Clan Weakness

Requires your blood

As with any extreme uses of a human power you can only do this once on night one, or twice on any night thereafter. (See Mechanics.) Feed a narratively appropriate amount of your blood to the victim, or have them continually latch onto your vein while you place your hand(s) on them and try to work.

Malkavians

Your power can also bring peace to those afflicted with supernatural mental ailments, notably the madness or hardships suffered by the Clan of the Moon: the Malkavians.  Note that this power cannot permanently remove a Malkavian’s primary clan weakness, though it does relieve the weight of it from their mind - almost entirely. They feel suffused with peace and lucidity, and a sense of emotional and mental well-being.

As above, feed them your blood - much more for an elder Malkavian, theirs is an old madness indeed - and begin your purge. They must be willing, as with any vampire target.

You gain their primary clan weakness however, or their personal form of madness as if it was your own. Have them describe it to you off-game so you can roleplay it for the next hour as being there. Nicely for them, they are at peace. You are not. Your character likely won't know this could even happen when you try this for the first time, though they might guess.