Hello, in Diablo 3 in the campaign you can hear the necromancer saying he/she serves rathma.
What does this mean exactly. Is the necromancer evil and trying to help revive Lilith?
Because isn’t it Rathma who is reviving Lilith in the cinematic opening cutscene for D4?
No, Ratham and his followers are not evil, they are natural and want to maintain the balance. Rathma did not “revive” Lilith. It was the Triune.
No, it is not Rathma he did not like his mother (Lilith) or father (Inarius).
“the triune who is responsible for helping Lilith return to Sanctuary, as you saw in our cinematic, they also worship the Prime Evils; and they are hastening their master’s return to Sanctuary.” - Blizzcon 2019, Harrison Pink
If you play D4 you will see how some of this plays out. If you do not want to pay D4 just check out YouTube clips.
Every Necromancer serves Rathma.
Rathma isn’t evil. He is a first generation nephalem and so is very powerful. He was the first necromancer and created their order and mandate. They serve the balance, knowing that tipping the scales too far from the extremes of Heaven or Hell will doom Sanctuary. A balance must be maintained between the two forces. He is a servant of Trag’Oul, who is a mysterious being, but it is theorized that it is a god, sort of the “spine” of sanctuary in which it was formed. Out of all of the heroes in Diablo, necromancers are probably the ones whose philosophy is the true salvation of Sanctuary.
In Diablo 4, I believe the narrative is being intentionally misleading when it comes to Rathma, and we will be seeing much more of him. He would be key in dealing with the conflict between Inarius and Lilith, his parents. He may also be one of the only entities powerful enough to stand against them. There is a trilogy of books called The Sin Wars which covers his story. I really enjoyed them and he is a very powerful being. If you want to learn a lot about the origins of Sanctuary and the life of Rathma, then I highly recommend reading them.
EDIT: Minor Spoiler Warning- What we saw in Diablo 4 cinematic either wasn’t Rathma or maybe it was a simulacrum.
In the Diablo 4 open beta, which allowed players to play through the prologue and act 1, you find out who a bit about the one who brought back Lilith, as well as what happened with Rathma. Based on your thread and question, I’m assuming that you didn’t play the open beta, as such, I’ll avoid say more than that, as it could be spoiler for you. That said, Avalon pretty much hit the nail on the head with his response.