Diablo 4 general - All shit will hit the fan this June

[Weeby Catto]

, I believe Lilith acheived the impossible in the very end and changed her nature, and this likely made her no longer a true demon, and probably died forever because of it.

I for one don't believe she has changed her nature, but she has always been for humans and always misunderstood because of her demonic nature.

Imo her seeming change seems to come from the fact that she met the protag of d4, and found hope in him.
You have to understand that before that, all she knows was Elias, whom she knows is selfish, but necessary to empower as humans against the tides of hell.

The evidence of her always loving(even if some blood needs to be spilled) and wanting the best for humans was her making that dagger for Rathma, she has made it before all these happened. She knew it is a weapon that can allow humans to ward off the prime evil, and it cost her part of her life force. Unfortunately, even Rathma doesn't believe on Lilith, and thus hid the weapon.

Then she met the protag, who was empowered, and fought with their lives against the prime evil and she found him/her worthy to sacrifice her life for.
That's why in her last moments her words were "I've fought for humanity all my life, and all I've got to show for it is you..."

In the choice between her life and empowering and protecting the humans against demons, she has always chosen the latter.

 

[Zenos Yae Viator]

I for one don't believe she has changed her nature, but she has always been for humans and always misunderstood because of her demonic nature.

she was made specifically, and only, to massage the ego of Mephisto, to have someone who is "almost" smart and cunning enough to beat him, to give him a real run for his money in endless strategy, games, politics and battles, but likely just always "almost", she's a being instilled with pure Hatred from the Concept of Hatred, her Dad.

So yea, the fact she chose to love an Angel, then her Children, create a sanctuary for them, and dedicate her life, and her essence, and maybe even her existence so that they could possibly win the grand battle against the forces in the Universe is a big change, Rathma was convinced she was doing it all for herself so she could beat Mephisto or something.