I doubt we'll see Sindri again. Popular concept is that his ascension to Daemon Prince wasn't finished by the time he was killed. Plus the daemon of the Maledictum listed him as a 'sacrifice'. Sacrificing an incomplete Daemon Prince might have completely destroyed Sindri's soul. But then again, nothing has been said on the matter of Soul Science. It's speculation at this point.
Well i do believe he is tied tot he daemon it self, as he was indeed listed as a sacrifice to him, so he most be part of the daemon, so if the daemon wants to return him that might be possible though. Eliphas......for example...
I doubt that any of the Primarchs will show up, unless it's in a flashback of somesorts. they're all off doing their own thing and aren't influencing anything in the 41st millennium
i can't imagine why not. at least in terms of a story. But you MUST consider this. Sindri was created and is owned, legally, by Relic/THQ. Even though THQ is bankrupt and Relic is as it is now, Sindri's character still belongs to THEM and as such will most likely NOT appear in BEhaviors games. Sadly I believe this also relates to Gabriel Angelos of the Blood Ravens and any other Dawn of War/ DOW II characters. The Blood Ravens may make an appearance, since GW owns the Chapter. But the characters however are another matter.
I REALLY want "SIIIIIIINNNNNDDDDDRRRRIIIII!!!!!!!", Araghast, Eliphas, Boreale, Macha (Eldar (famous on 4Chan)) to be in the game! Also if you bring in Cultist Chan I WILL FUCKING NAME ALL MY CHILDREN AFTER THE DEV TEAM!!!!