The council of archangels met to decide humanity's fate long after Inarius and Lilith secretly established Sanctuary for the Nephalem Diablo IV Gold, the offspring of both man and angel. Tyrael was the one who cast the decisive vote; as a result, the rest of the Angiris Council would hold him accountable for that decision, resulting in his death prior to Diablo 4 for the sake of humanity. His job in the impending game is as of now hazy, however there are a few likely ways this critical figure could factor into the fate of the series.
By tearing off his own wings and plummeting to Sanctuary, where the Nephalem's heirs live, Tyrael becomes the Fallen Star in Diablo 3. Tyrael takes control of the Black Soulstone and banishes the Prime Evils with the help of a powerful descendant. Tyrael was the one who sent his companion to Pandemonium in order to eradicate death itself when Maltheal, the Archangel of Death, pursued the stone and turned against all of his allies.
Tyrael decides to keep his mortal form, but he and his angelic brothers reunite to become both the Aspect of Wisdom and Justice. At the end of Diablo 3, he wonders if his new mortal companion, who may be corrupted, will one day pose a threat to Sanctuary, Heaven, and Hell—or even life itself. It's likely that the Aspects of Wisdom and Justice won't just stand by as Inarius leads an army through Hell in search of Lilith, his former love.
In the most recent Diablo 4 movie trailer, which was released by Blizzard, Inarius is shown facing Lilith with armies at their backs. Although Tyrael is not directly involved in this scene, his creation of the Horadrim and influence over the various Paladins of Sanctuary indicate that he is. On the battlefield buy Diablo 4 Gold, light and darkness clash, and Tyrael, who is now dead, is somewhere in between.