A named threat of Scarlet Cave, encountered rarely and never in numbers - real Dungeons & Dragons statistics, no auto-computed shortcuts.
Layered on top of the module's own combat AI, which still picks targets and positioning. The fight below moves through real hit-point-gated phases; every save DC and attack bonus computes from the stat block above at runtime.
She reads the battlefield for real spellcasting talent every round and locks her whole kit onto whoever has it - anyone else is only ever her fallback.
A stacking hush settles onto her chosen mark.
A chance to strip a ward outright, and then a wide silence-and-dispel she carries in spirit rather than as a formally granted spell - she has no true spellbook to hang an Epic Spell on, and the dossier says so plainly.
CR 10 is set against Scarlet Cave's own real ambient ceiling, not auto-computed from level alone - a genuine Ranger 4 / ShadowbaneInquisitor 6 build at 10 total levels.
Hit points (80) follow this project's own average-hit-dice convention, and every save/attack bonus derives from the ability scores above at runtime - nothing here is hardcoded past the phase gates themselves.
Boss-flagged (bypasses the drop-rate roll, two loot-generation passes) and gated to a single spawn - only one Dame Ysabeau Thorne is ever up in Scarlet Cave at a time.