Tyrael makes the decision to remain mortal, but he and his angelic brothers reunite to become both the Aspect of Wisdom and Justice D2R ladder items. He wonders at the conclusion of Diablo 3 whether his new mortal companion, who may have been corrupted, will one day threaten Sanctuary, Heaven, and Hell—or even life itself. As Inarius leads an army through Hell in search of Lilith, his former love, it's possible that the Aspects of Wisdom and Justice won't just sit back and watch.
Inarius is shown facing Lilith with armies at their backs in the most recent Diablo 4 movie trailer, which was released by Blizzard. Tyrael's role in the creation of the Horadrim and his influence over the various Paladins of Sanctuary suggest that he is, despite the fact that he is not directly involved in this scene. Light and darkness clash on the battlefield, and Tyrael, who has passed away, is somewhere in between.
Unless circumstances force him to take potentially rash action, it is possible that these mediators will feel his presence. Near the end of Diablo 2, Tyrael actually feels the effects of destroying the Worldstone. In place of that enigmatic object that protected Sanctuary from both Heaven and Hell, he now protects the land. Tyrael doesn't seem to be going any further than the Pandemonium Fortress, where he might give people who stay and listen advice similar to that of Deckard Cain.
Five playable Diablo classes have been announced thus far, all of which are reimaginings of previously available options. Tyrael may play a role in the conflict and offer players the chance to take on angelic or demonic powers in exchange for service to Sanctuary because each of the previous installments offered something new buy diablo 2 resurrected items. This sort of expert could without a doubt follow on the multi-tree progress recently proclaimed for the series.