There is a short story by Gala Galaction which says that a serial killer wanted to convert to Orthodoxy, but he had killed almost 100 people. But he wants to convert and not stop the kills. To convert and keep on killing.
The guy kills the few priests/monks who tell him that he should stop with the kills, he can’t join Orthodoxy and still keep on killing people. He reaches the 99 limit, and knows that at 100 he will die.
One last person tells him that it’s OK to join Orthodoxy and still keep on killing. But prior to continuing his kills, he should do some rituals. And he prays for lots of years in a church.
At some point, he does a good deed by killing a person (he kills one devilish person who wants to marry an innocent person) and dies and presumably goes to heaven.
There is a saying in Romanian proverbs which says you can’t do impure, lust actions (the proverb is more plastic) and still have your soul in heaven. While this is true, there are some exceptions to this rule, which fascinate me. See the above example. The guy kills not for himself, to derive pleasure of killing, but for others, to help others. It’s really tough for me how you can have sex for the good of others :) , yet the general principle that you can do some things and still be an Orthodox is a nice one.