Eternal Decks · Board game rules
How do I remove the WITCH B3 deck from my Eternal Decks in story mode?
Quick answer
In Solo Story Mode, remove the Witch Eternal card and all 7 non-Ability cards from her deck; only the Witch's Ability Card ("Beloved Cat Card") stays in play from Stage B onward.
Details
In Story Mode "The Alchemist and the Cat," the Witch Eternal (B-3) is not used at all — you return the Witch Eternal card and all cards from her deck except the Ability Card back to the box [p.56 — SOLO PLAY]. The Ability Card itself is kept and repurposed as the "Beloved Cat Card," which appears starting in Stage B [p.56 — SOLO PLAY].
Specifically for Stage B setup, you prepare only the Beloved Cat Card (the Witch's Ability Card) in the top row of the Field, placing a Key on top of it, while the Witch Eternal and her other seven cards go back in the box [p.57 — Changes to Stages B, C, and D]. You must Revive the three remaining B Eternals before you can gain the Beloved Cat and its Key. If the six Jewels haven't been generated by the time you gain all four Keys, move the Beloved Cat to the Stage B Card, just as you would with a Revived B Eternal [p.57 — Changes to Stages B, C, and D].
The Beloved Cat has no ability and no Curse of its own once placed this way, and its associated Jewel can only be used once across Stages C–E, so choose the timing carefully [p.57 — Changes to Stages B, C, and D].
Watch out: Also note that in Stage C Expert Mode, Story Mode replaces the usual E Eternals with B Eternals — but since the Witch is removed from the game, she will not appear even if B Eternals are drawn for that substitution [p.57 — Changes to Stages B, C, and D].