Silence as written in PF2 is
PF2 Silence wrote:
Range touch; Targets 1 willing creature
Duration 1 minute
The target makes no sound, preventing creatures from noticing it using hearing alone. The target can't use sonic attacks, nor can it use actions with the auditory trait. This prevents it from casting spells that include verbal components.
Heightened (4th) The spell effect emanates from the touched creature, silencing all sound in or passing through a 10- foot radius and preventing any auditory and sonic effects in the affected area. While within the radius, creatures are subject to the same effects as the target. Depending upon the position of the effect, a creature might notice the lack of sound reaching it (blocking off the noise coming from a party, for example).
It can only be used at touch range. Meanwhile, the Ascendant is described as staying atop their dais and attempting to prevent PCs from approaching. Not to mention it requires a willing target in PF2
I feel like the encounter was written with the PF1 Silence in mind, which is
PF1 Silence wrote:
Range long (400 ft. + 40 ft./level)
Area 20-ft.-radius emanation centered on a creature, object, or point in space
Duration 1 round/level (D)
Saving Throw Will negates; see text or none (object); Spell Resistance yes; see text or no (object)
Description
Upon the casting of this spell, complete silence prevails in the affected area. All sound is stopped: Conversation is impossible, spells with verbal components cannot be cast, and no noise whatsoever issues from, enters, or passes through the area. The spell can be cast on a point in space, but the effect is stationary unless cast on a mobile object. The spell can be centered on a creature, and the effect then radiates from the creature and moves as it moves. An unwilling creature can attempt a Will save to negate the spell and can use spell resistance, if any. Items in a creature's possession or magic items that emit sound receive the benefits of saves and spell resistance, but unattended objects and points in space do not. Creatures in an area of a silence spell are immune to sonic or language-based attacks, spells, and effects.
So if we were just playing at home, I'd suggest they change it to a typical range - probably 30', Will save, and degrees of success to match some similar spell
But what about in PFS? Just ciest la vie, and the Ascendant doesn't use that spell after all? Or use GM prerogative to allow the boss monster a special version of Silence that works how the encounter is written?
edit: a third option that just occurred to me would be to replace Silence with another same-level spell that might serve the same purpose of foiling a caster
