Mother Bellow bound her own healing to the cave the day she claimed it as a shrine. Kill the totem she raised and the cave stops answering her - but she will not take that quietly.
She heals a flat amount off it. No prior boss here depends on an external, independently-killable creature that ISN'T an offensive minion - it is a pure defensive dependency the party has to go find on purpose.
The first round the totem is confirmed dead
Ruin
Her epic spell answers as a grief-burst, once - negative energy in a 9m radius centred on her.
Why These Numbers
Scarlet Cave's real ceiling was Kessandra Vorn at CR14 (round 8); Mother Bellow is pitched one notch above at CR15, into 3 of the area's remaining Sparky slots.
She is the bestiary's first Totem Rager - a Minotaur matriarch cloned from red_minotaur, with a new support blueprint (scv5_totem, cloned from bele_toad) built specifically to carry her Totem Bond dependency.
Real Epic Spell: Ruin (id 640/878) - Scarlet Cave's existing boss (Kessandra) already used Dragon Knight, so Ruin went here; the grief-burst framing fits a boss whose capstone is a reaction to loss rather than a scheduled climax.
How It's Wired
pattern
new build — cloned from red_minotaur; new support blueprint scv5_totem.utc cloned from bele_toad