Taken from DLSite: https://www.dlsite.com/maniax/work/=/product_id/RJ01067637.html

It's got some surprisingly dark moments, regardless it's pretty solid.

Base +5, Sylphvine +6, CocoaRobbins +6, MrDanger +6, hyliades +6, andystevens1997 +9, MorTho123 +6, rockball +6, ♫SiL♫ +6

https://xion-laika.booth.pm/items/4849121
https://xionlaika.gumroad.com/l/rsueh?layout=profile
https://www.pixiv.net/en/artworks/109391561
https://twitter.com/spacelaika13
https://xion.fanbox.cc/

Base +19, Miles Edgeworth +70, MorTho123 +6, Sylphvine +6, dyf123 +16

But why do they kill each other? this felt more like a regular manga that I forgot to fap and got into the plot.

Base +13, andystevens1997 +9, bones1885 +6, danielwain +9, KiraKazumi +6, MorTho123 +6, Sylphvine +6

@The Mike
The implication seems to be that each of them thinks they're the real person and the other is a dangerous doppelganger.

Base +7, GenericDisplayNames +7, MorTho123 +6, finnick8 +8, mofashao +6, rockball +6, Sylphvine +6, Kotovsky +6

Palty the Sage is probably the most excited one to find her clone among the whole Mirror Collection series.

Base +5, Taedium +6, jason12052011 +7, MorTho123 +6, Genoard +6, Feladrance +6, baseddogswag +6, rockball +6, ♫SiL♫ +6, Donut_Flower +6, Sylphvine +6, Kotovsky +6

Not enough sex, too much exposition.

Base +6, mofashao +6, justinneil -6, QuintessenceQ -8, zenith45 -8