Unfortunately I had to do a completely new run of elden ring to make it to the dlc and had already put in about 100 hours.
Now that I'm in the dlc I'm about halfway through it and starting to get burnt out.
I can tell it's really good. I think I'm just burnt out on Elden ring because it's all I've been playing lately in an attempt to unlock the dlc
Tldr I wish I would have had my Xbox and my old character to jump straight into the dlc instead of starting over on ps5 and playing through nearly the entire base hame.
He is Radahn's soul inhabiting Mogh's body (There are Omen horns on his model, and phase one of the fight even uses Bloodflame).
Malenia went to Caelid on Miquella's orders to kill Radahn's soul with the scarlet rot while keeping his body alive (much like what happened to Godwyn the Golden). Then after the tarnished kills Mogh, his body was whisked away to the Shadow Realm (where dead things end up) for Miquella to combine the two into his new consort. Why he couldn't just drag Radahn's body down too idk, it's Empyrean shit - maybe creating a new demigod consort was easier than convincing his brother to do incest instead of just staring at the stars all day. Meanwhile Miquella shedding his body all over the place is kind of like what Ranni did in the main game. The damn twink set everyone up!
This is explained in the quest with Ansbach and Freyja in the Shadow Keep Storehouse, but given fromsoft storytelling I'm probably wrong on a detail or two.
In Messmer’s castle, I think most of the NPCs as well as notes you pick up refer to both of the two required vanilla bosses’ corpses being moved or otherwise manipulated. They also talk about a ritual, I believe one NPC even connecting the dots for the player and saying explicitly what the ritual is for and that the corpse is for the ritual. It’s the most coherent and opaque FromSoft lore has ever been.
Whether it’s GOOD that that’s the boss is up for debate, I certainly don’t agree. But it isn’t an arbitrary decision.
Let me know if you are able to recall which npc it is that talks about the ritual. Would love to read their lives. But definitely don't stress about it.
Redmane Freyja and Sir Ansbach. You bring a letter to Freyja from Ansbach who elaborates some. You also bring a scroll about the ritual to Ansbach who lays it all out quite clear. The dialogue is all on fextralife so you don’t have to replay the entire DLC