No, Unicorns and alicorns don’t kill non-virgins nor are they evil. The unicorns have a evil counterpart known as the Bicorn. Bicorns are known for killing non-virgins who have good hearts and are loyal to their families. Go to this link right here. https://mythology.wikia.org/wiki/Bicorn#:~:text=The20Bicorn20(literally20meaning2022two,has20some20shape2Dshifting%20abilities.
Its a very interesting creature, But its a shame that not that many people talk about it.