[quote=@Lawful Newtral]
Say we have a Nephilim. And said Nephilim one day made a decision to spare a Revenant or other being of chaos from complete purging. Would this Nephilim be punished and if so, how and how severe?
[/quote]

Sounds like this falls under the noble jurisdiction of [@Arkaotic]. 

EDIT: Didn't see his post when I replied :lol

But if it were me, I'd guess they'd have a lot of punishment and distrust to deal with. I imagine something like... 

They aren't trusted enough to go on missions alone any more, so they must always be escorted along by a senior Nepher. Perhaps they had to spend time re-training like a new initiate, to make sure the lessons [i][b]sunk in this time.[/b][/i]

Sidenote: If you would be so kind, let the "Revenant or other being of chaos" your dude sparred be a Fleshspinner instead of a Rev, who was caught drinking the blood of a victim. BUT that victim was discovered to be a rapist and general thug, so your character felt sympathy and spared the fleshy blood-drinker b/c their only crime was killing a rapist/murderer/thief/scumbag. 

And let that Fleshspinner be named... Rayu :golfclap

(if you're okay with that)