I've been a fan of Sylvanas as a character since Warcraft 3, and my WoW main is a Blood Elf who still believed in the Ranger General until Shadowlands. In the Battle for Azeroth War Campaign the Horde players are forced to choose between Sylvanas loyalist and Saurfang rebel, and despite my better judgment I chose to believe in the Dark Lady, Sylvanas Windrunner, my Ranger General, because my heart is joyfully foolish beyond my jaded brain. Looking at sum total of the game's lore I understand how we got the Sylvanas we have, but it was refreshing to see her younger self come to terms with who the rest of her soul became. She isn't forgiven because that piece of her old self returned, and despite what critics on the internet say at no point is she ever truly forgiven. I surely don't forgive her. But also I have been a worse version of myself and there are people that were important to me that hurt and they cut me out of their lives! and as much as I might want their forgiveness I can't demand it, and they will treat me as toxic for the rest of our lives and I can't begrudge them that because I hurt them badly. In the end forgiveness is nice, but if you don't get it then you don't get it, doing right and being better is actual goal you should be focused on, along with acceptance that you F'd up and understanding exactly how. I wouldn't call it a mercy, but Sylvanas got a tool for growth you don't typically get in the real world. The true view from yourself before you fell into a dark patch is a tool for growth and development but would cause me such significant pain, and that pain would drive the lesson further.