Who did we kill at the end of Diablo 3?

By now, I've killed Diablo countless times, but one questions always pops in my head. Who did I exactly kill? Diablo or seven Lords of Hell?

In cinematic after act 3, when Imperius sees Diablo, he calls him - "My old enemy". Also, when he sees Diablo as Leah, he shouts at him to show his true form - as Diablo. Actually quote is - "My old enemy, you can't hide from me... no matter what form you choose to wear. Let your true form be revealed... Diablo!"

However, when we fight Diablo, he talks about himself not as one being, but as legion.

So, question is, at the end of the game, who did we kill - Diablo or seven Lords of Hell (Diablo, Belial, Azmadon, Baal, Mephisto, Andariel and Duriel)?

Solution 1:

The closing cutscene shows Diablo's body fizzing away (Eviltrons colliding with Holitrons in the atmosphere emitting a burst of gamma rays, I guess), but the black soulstone (which we already know is imperfect/unstable) survives and plummets down to... who knows where.

So... we didn't kill anyone. Diablo had become the Evil Overmind of the Team Evil Collective, and we just destroyed his physical body... because sequels.

Solution 2:

Diablo has the souls of the seven Lords of Hell within him. As implied by Leah's control over the Black Soulstone, the souls in the soulstone are still somewhat conscious as they were able to fight back and attempt to wrest control. However, Leah alone was able to prevent it, which implies that the souls aren't particularly powerful in their present state.

Based on this alone, the souls within Diablo are under his control and their power is his. However, as Diablo dies, there is no longer anything to maintain control over the souls within him.

Based on evidence from the Black Soulstone, it is hard to say whether destroying the stone would have released the souls within or destroyed them. Adria leads you to believe that destroying it would destroy the souls, but there's not much proof beyond her testimony.

My theory is that Diablo, as well as all of the other Evils, are as dead as Diablo was in the first game. It's just a matter of finding another host.

To answer your question, who did we kill? Leah.

Solution 3:

We didn't kill any of them - in the ending cutscene after you defeat Diablo and the corpse of Diablo falls from Heaven, his body begins to disintegrate and you can clearly see the black soulstone drop to Sancutary.

The soulstone is still intact, along with the souls of the seven evils inside of it. We killed the physical manifestation of Diablo, but his soul and the souls of the six other evils along with potentially the soul of Leah are still contained within the soulstone, which is somewhere in Sanctuary.

Chris Metzen has hinted that Leah's spirit may be "floating around somewhere" after the events of Diablo III. Covetous Shen also tells the player not to underestimate Leah's spirit and implies he had seen something similar before.