All souls games have bad endings but Wylder's ending is a dick move to like the other nightfarers.
Imagine, you and 7 others have been struck in basically limbo for however long, your victory over the first nightfarer only revealed that there were 7 more. Finally however, you defeat the primordial nightlord...
Just for Wylder to come and replace him because "Mah sister." The same sister who herself was content with dying to save him. Like imagine all that work just for this dick to replace the night lord to "save" his sister by putting her back in the same limbo hell loop.
Sure, the Recluse being mother figure she is fine with it, because "Oh family" because she's still regretting the fact her inability to hug her child basically led to the mess they're in, but for everyone else? He's a dick.