Larian Studios Forums Divinity: Original Sin 2 Divinity - Original Sin 2 - General [Spoiler] Ending with Lucian

Hi!
For the second time, I'm finishing this wonderful game, and try the different endings.
However, I can't manage to unlock ending where lucian remain the divin: I accept his deal, I fight an kill braccus with him, and despite, I can choose to do whatever I want with the source, while Lucian is watching me. It's not logical, right?
Is it a bug? I pretty sure that, in my previous game, lucian didn't give up and remains the divine... Did I dreamed? Is that end really exists?
Thanks!

Since you are already there.

Immediately after winning the final fight, after your companion dialog, you choose claim divinity(this is actually miss leading), then you are presented with 3 choices(may get additional origin char specific choice). The 3rd one, purging all source is what you are looking for.

You can do a save game at dialog and try all of them.