@Twin I don't know how far ahead the manga is, but based on what's translated so far, there's clearly not enough for a 2nd season sadly. I do agree with you tho.
@cgr Maybe there is more to the conditions than what it seems, the act of killing staining the soul is a classic staple of magic fiction (and even the "real" ones too), but Chise never had any malice or desires in her "kills", but Liam is member of a family specialized in fighting peoples, Philomela's family is too good in stealth to have any normal work and Lucy has had a complicated life.
A surprise translated chapter have appeared, i hope a group really have picked up the manga or i have to wait for years before i can read this chapters (it feels like i am reading those mangas that only drops 1-4 chapters a year)
@alacaelum
liam and philomena do make sense, though I felt like it was possible neither killed since Liam left his house , and philomena's job was spying not killing (though I agree spying could easily lead to killing).
lucy is the one I really didn't expect since her family was killed 8 years ago (so she's around 7~9?) and her family's specialty was making/copying/binding grimoires - not really something that would lead her to kill anyone. I really doubt seth was cruel enough to let his kid sister do something like killing after he became her guardian.