"A qlippoth can present itself as a standard action to assault the senses of all living creatures within 30 feet. The exact effects caused by a qlippoth’s horrific appearance vary by the type of qlippoth. A successful Will save (DC 10 + 1/2 the qlippoth’s Hit Dice + the qlippoth’s Charisma modifier) reduces or negates the effect. This ability is a mind-affecting gaze attack."
That is the rule. My question is: this abilty is always active like a gaze attack? Or the qlippoth active it with a standard action and all player in the area throw the saving dices?
Thanks for all answers
Unless the specific qlippoth entry would indicate otherwise, this generic description of how Horrific Appearance works clearly states that it's performed as a standard action.
Ok with that... But then it remain active for all the battle or run out instantly? My playgroup has many doubt about this trait...
How long the effect last will depend on the specific Qlippoth ability entry.
To choose one at random:
Creatures that succumb to a cythnigot’s horrific appearance become sickened for 1 round—a cythnigot’s horrific appearance only functions to a range of 10 feet. Once a creature makes a saving throw against a particular cythnigot’s horrific appearance, that creature is immune to the horrific appearance of all cythnigots for 24 hours. A spellcaster that has a cythnigot as a familiar is immune to the horrific appearance of all cythnigots, and also gains a +4 bonus on saving throws made against any qlippoth’s horrific appearance.
So, the Cythnigot's Horrific Appearance is activated as a Standard Action. On a failure the creature is sickened for 1 round. The Cythnigot's Horrific Appearance only affects those creatures in 10ft.
Once a creature has made a save against a specific Cythnigot's Horrific Appearance they are immune for 24 hours. So on a save you're not affected and are immune for 24 hours. On a fail you are sickened for 1 round, then are immune for 24 hours - 1 round.
How long an effect lasts and whether a creature can be affected by it multiple times depends on the specific creature's entry.
But I think as a GM you are trying to figure out if you get to continuously affect the player characters without needing to spend further actions and the answer is no.
The ability lasts for as long as it says it lasts, if it doesn't mention a duration it is instantaneous. If the qlippoth wants to affect them again it might be possible (unless the entry mention immunity like the Cythnigot's does), but would need to acitvate the ability again as another standard action.