The FF Chronicle Barrier Creature (Summon: Fenrir) produce additional mana when placing the last Chronicle indicator due to other effects (Enduring Vitality). As a result, it is tapped and will not be sacrificed immediately after all abilities are resolved. The page will freeze and wait for my operation. At this point, the FF Chronicle Barrier Creature is tapped, with three Chronicle indicators, and all ability entries are grayed out. Other spells are cast later, and only then will the FF Chronicle Barrier Creature be sacrificed.