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.
Bloodscent, Reckless Swing, Fury Roar, Thick Hide, Second Wind, Cave-In Smash, Endless Fury - one climbs into the next on a fixed clock that never once checks his health.
Endless Fury settles in for good, whatever state he's in.
Nothing about the ladder's climb undoes itself.
CR 9 is set against Scarlet Cave's own real ambient ceiling, not auto-computed from level alone - a genuine Barbarian 6 / Frenzied_Berserker 3 build at 9 total levels.
Hit points (100) 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 Grask Bloodmaw is ever up in Scarlet Cave at a time.