Guide
How the kit works
Lucia starts with 60 Dream Points when she enters the battlefield. With enough Energy, use EX Special Attack: Symphony of the Reaper - Daybreak (Special). Outside Dream, it gives her 60 points, enough to reach the 100 needed to enter Dream. It is a Harmony, so it also applies Darkbreaker to the squad for 20 seconds.
Entering Dream activates Ether Veil: Wellspring and triggers a Quick Assist. Wellspring gives the squad 5% Max HP for 40 seconds. Repeated activations extend its duration, up to 300 seconds. After the EX Special Attack, Lucia can immediately follow with the fifth hit of Basic Attack: Orbital Combo.
In Dream, a Whim costs 25 Dream Points and becomes a Harmony. Each skill upgrade gives the squad 20% DMG for 12 seconds. When another active character hits an enemy, Lucia can spend 25 points on an Aftershock for the same buff. An upgrade or Aftershock prevents another Aftershock for 8 seconds. Lucia exits Dream when she runs out of points or leaves the Ether Veil.
Use Ultimate: Charge, Great Armor! for an area strike and an eight-second Starlight Convergence that regenerates the active character's HP inside it. Its charge can be steered and extended for up to three seconds. In Dream, the Ultimate also stores one return to Dream for the next time Lucia exits it; that effect cannot stack.
Build and why
Use four pieces of Moonlight Lullaby. Its two-piece bonus gives 20% Energy Regen, and its four-piece effect gives the squad 18% DMG for 25 seconds when Lucia uses an EX Special Attack or Ultimate. Both skills already fit her support rotation.
For the remaining two slots, Yunkui Tales gives 10% HP. Swing Jazz is an alternative with 20% Energy Regen. A four-piece Swing Jazz is another option: its Chain Attack or Ultimate buff gives the squad 15% DMG for 12 seconds.
Choose Percent HP on discs 4, 5 and 6. Look for Percent HP first in substats, followed by HP. Lucia's Darkbreaker grants more Sheer Force based on her initial Max HP, with that bonus reaching its maximum at 24,000 initial Max HP. Her Harmony damage and Ultimate's HP regeneration also scale with Max HP.
Dreamlit Hearth is the first weapon choice. It gives Energy Regen and, when Lucia activates or extends an Ether Veil, grants the squad 25% DMG and 15% Max HP for 45 seconds. Weeping Cradle is an alternative that provides off-field Energy Regen and increases damage against enemies Lucia hits. Unfettered Game Ball is another option if her attacks trigger Attribute Counter, giving CRIT Rate against the affected enemy.
Leveling priority
Follow the game's order: raise the core passive first, then Special Attack, Chain Attack, Basic Attack, Assist and finally Dodge. The core passive controls Dream and its squad buffs, while Special Attack is a practical way to start that setup.
For maximum ascension, gather 800,000 Denny, 4 Basic Support Certification Seal, 32 Advanced Support Certification Seal and 30 Ruler Certification Seal.
For all skills, gather 2,905,000 Denny, 25 Basic Ether Chip, 75 Advanced Ether Chip, 250 Specialized Ether Chip, 5 Hamster Cage Pass, 9 Crimson Miasma Spike and 60 Higher Dimensional Data: Corrupted Dreamsteel.
Mindscapes worth it
Secret Friend can keep Dreamer's Nursery Rhyme going. Each skill upgrade grants an Echo stack, up to four; when the buff ends, one stack is spent to reapply it. The Never-Ending Journey is an option for Lucia's own damage: inside any Ether Veil, it gives her ATK based on initial Max HP and makes Harmony always crit with 30% more Harmony CRIT DMG.
Late-Night Hours gives the squad 100 Decibels when an Ether Veil is activated or extended, once every 15 seconds. The Best Partner and Dream Watcher raise skill levels by two. If your goal is squad buffs, those two are less urgent places to stop; later mindscapes still require the earlier ones.
Teams
Bring at least one Rupture or Stun character to activate Lucia's extra 30% CRIT DMG when she applies Darkbreaker. A Rupture teammate can also use the Sheer Force Lucia grants. The condition does not require a particular attribute.
Yidhari and Manato are Rupture options named for Lucia; a team with both gives her two teammates who meet the condition. Yixuan is another Rupture option, while Dialyn, Ju Fufu and Pulchra can fill a Stun slot. Banyue is a further Rupture choice.
Pan Yinhu is listed as a teammate and can fill a Defense slot alongside a Rupture or Stun teammate. Once Dream is active, switch to the character you want attacking so their hits can trigger Lucia's Aftershock. Stay inside the Veil to keep Lucia in Dream.
Common mistakes
Do not build only for Lucia's personal damage if you want her squad buffs. Percent HP helps her Darkbreaker scaling, and a teammate with Rupture or Stun is needed for the extra CRIT DMG.
Do not spend all your Dream Points on upgraded Whims without considering the Aftershocks you want from your active teammate. Watch the eight-second Aftershock lockout too. If Lucia leaves the Ether Veil, Dream ends even if points remain.
Do not assume the Ultimate's healing follows a character indefinitely. Starlight Convergence lasts eight seconds; its regeneration ends four seconds after leaving the area or immediately when that character switches out. In Dream, an EX Special Attack can extend active Wellspring by 16 seconds, while the Ultimate extends it by 32 seconds.
