The Day The Cosmos Fell
The Day The Cosmos Fell is a 4★ Light Cone for the Path of Erudition in Honkai: Star Rail.
A farmable 4-star Erudition cone that grants flat ATK plus a strong CRIT DMG boost when an AoE attack hits at least 2 enemies with matching Weakness, making it a solid pick for many blast/AoE damage dealers.
Increases the wearer's ATK by 16%. When the wearer uses an attack and at least 2 attacked enemies have the corresponding Weakness, the wearer's CRIT DMG increases by 20%, lasting for 2 turn(s).
"Molten Cheese Tart! You are in charge of disarming the planet's lookouts with your charm!" "Gray Bean Paste! You will be in charge of breaching the planet's line of defense!" "Salty Rimeplume! Bring us the head of the planet's leader!" "My lord, what are you going to do!" "I shall pretend to be an adorable kitten to befuddle these stupid humans!" That day, the Cosmos remembered... the terror of being ruled by them.
How to read this Light Cone page
Every Light Cone has exactly one passive effect tied to the wielder's combat performance; that effect scales up as you Superimpose it from S1 to S5 — use the S1-S5 buttons above to see the exact numbers at each level instead of guessing or interpolating. A Light Cone only delivers its full value on a character who shares its Path; "Characters who use this cone" lists every character on that Path, while "Best users" is a narrower list pulled from real build consensus, not a guess.
Base stats (HP/ATK/DEF) are shown at Lv80 for every cone of the same rarity so they can be compared directly; a 5-star cone will always edge out 4-star and 3-star ones here — the real difference lives in the passive effect, not the flat stats. The "Alternative cones on the same Path" section suggests a few other options if you do not own the signature cone yet, or want to compare before spending ascension materials.
See the full list on the Light Cones page, or check terms in the HSR Glossary.