Guide
How the kit works
Before combat, use If You're Happy and You Know It to enter with Numinosity for three turns. If you need to refresh it, Where'd the Gifts Go grants the same effect: allies gain 24% All-Type RES PEN while it lasts. Its duration drops at the start of Tribbie's turns.
Use Guess Who Lives Here to hit all enemies and create a Zone for two Tribbie turns. Enemies in it take 30% more damage. After an ally attacks, the Zone deals one instance of Quantum Additional DMG per enemy hit, all directed at the enemy with the highest HP among those hit.
Busy as Tribbie triggers an all-enemy Follow-Up ATK after another character uses their Ultimate. Each other character can trigger it once until Tribbie uses her Ultimate and resets their counts. Her Follow-Up ATKs also build stacks that increase her own damage. While the Zone lasts, her Max HP rises by 9% of the sum of all allies' Max HP.
Build and why
For four relic pieces, start with Poet of Mourning Collapse. Its two-piece bonus gives Quantum DMG, while four pieces lower SPD and give CRIT Rate if her pre-battle SPD is below 110 or 95. Check that threshold before relying on the bonus.
Eagle of Twilight Line is an alternative: its four-piece effect advances Tribbie's action after her Ultimate, although its two-piece Wind DMG does not help her Quantum attacks. Longevous Disciple gives Max HP and can build CRIT Rate when she is hit or has HP consumed. Genius of Brilliant Stars is another option for Quantum DMG and DEF ignore.
Pair the relics with Bone Collection's Serene Demesne for Max HP. At 5,000 Max HP, it also gives the wearer CRIT DMG. Fleet of the Ageless offers Max HP and an ally ATK bonus at 120 SPD. Lushaka, the Sunken Seas gives Energy Regeneration Rate and buffs the first character's ATK if Tribbie is placed elsewhere in the lineup.
Use CRIT Rate or CRIT DMG on the body, HP Percentage on the feet, Quantum DMG Boost or HP Percentage on the sphere, and Energy Regeneration Rate or HP Percentage on the rope. For substats, look for CRIT Rate first, then CRIT DMG and HP Percentage.
If Time Were a Flower is the first Light Cone choice: her Follow-Up ATK activates its Energy recovery and team CRIT DMG buff. Dance! Dance! Dance! advances the team's actions when she uses her Ultimate. Memories of the Past is an alternative that restores Energy when she attacks, once per turn.
Leveling priority
Follow the game's order: level Guess Who Lives Here first for the Zone and its damage, then Where'd the Gifts Go for the team RES PEN. Level Hundred Rockets next, followed by Busy as Tribbie. The Talent still matters for her Follow-Up ATK damage.
Maximum ascension needs 308,000 Credit, 65 Darkveil Moonlight and 15 each of Fear-Stomped Flesh, Courage-Torn Chest and Glory-Aspersed Torso. To raise all skills to their maximum, you also need 3,000,000 Credit, 8 Tracks of Destiny, 18 Firmament Note, 69 Celestial Section, 139 Heavenly Melody, 12 Lost Echo of the Shared Wish, 41 Fear-Stomped Flesh, 56 Courage-Torn Chest and 58 Glory-Aspersed Torso.
Eidolons worth it
Rite of Sugar Scoop is a good early stopping point to consider. While the Zone lasts, an ally's attack adds True DMG equal to 24% of that attack's total damage to targets that received the Zone's Additional DMG.
Peace of Empathy Bond is another team-focused upgrade: while Numinosity lasts, allies' damage ignores 18% of the target's DEF. Morrow of Star Shine is worth considering for Tribbie's own damage. Her Ultimate launches her Talent's Follow-Up ATK, whose damage increases by 729%.
Guide of Dream Tour improves the Zone's Additional DMG and adds another instance when it triggers. Trove of Morning Glow and Clock of Wonder Origin raise skill levels rather than adding a new effect. You can stop before them if you do not want the later upgrades, but they cannot be skipped on the way to E4 or E6.
Teams
Argenti, Serval and Herta are other damage options named for Tribbie. Gallagher or Lynx can take the sustain slot instead of Lingsha. Pick the damage dealers around the encounter rather than assuming the whole team needs to be Quantum.
Other allies' Ultimates trigger Tribbie's Follow-Up ATK once per character between her Ultimates. Their attacks also supply Energy based on the number of targets hit. Keep the Zone active so their attacks can trigger its Additional DMG.
Common mistakes
Do not refresh Numinosity blindly every turn. Check its remaining duration, especially after entering with the Technique. Both Numinosity and the Zone lose duration at the start of Tribbie's turns, so watch their counters when planning her actions.
Do not expect every ally Ultimate to trigger a Follow-Up ATK indefinitely. Each other character gets one trigger until Tribbie uses her Ultimate to reset the counts.
Do not chase a SPD-dependent set bonus without checking your actual SPD. Poet of Mourning Collapse wants low pre-battle SPD for its CRIT Rate thresholds, while Fleet of the Ageless needs 120 SPD for its team ATK bonus. HP also matters: dropping too much of it reduces the value of Tribbie's HP-scaling damage.
