Something Irreplaceable
Something Irreplaceable is a 5★ Light Cone for the Path of Destruction in Honkai: Star Rail.
A 5-star Destruction Light Cone offering a large ATK boost plus self-sustain and a self-buffed damage window that triggers simply from defeating enemies or being hit, giving a powerful and easy-to-trigger survive-and-nuke loop.
Increases the wearer's ATK by 24%. When the wearer defeats an enemy or is hit, immediately restores HP equal to 8% of the wearer's ATK. At the same time, the wearer's DMG is increased by 24% until the end of their next turn. This effect cannot stack and can only trigger 1 time per turn.
"Should a day come when even I'm not here anymore, please look after this database, Svarog." (Who is this... Why is this message in my records...) "Do you have something that's irreplaceable, Svarog?" (Irreplaceable... broken parts... can simply be replaced...) "You'll definitely find it one day, Svarog." (Such things... will only cause trouble...) "When that time comes... You should leave this place behind."
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.