Why is Sylvanas the same boss as Kel-thuzad in the Sanctum of Domination, that didn’t make any sense at all.
Kel’thuzad was the one that that was responsible for destroying Sylvanas home, surely she knew that the only reason that the elves were slaughtered was to raise Kel’thuzad from the dead,
That bit didn’t make any sense to me why they were bosses in the same raid. Explain please.
The wow writers have no clue either
Just wait for the Maw arc where Sylvanas revives Arthas and marries him.
Danuser has already submitted the drafts.
I didn’t play this expansion; did we definitely kill Kel’thuzad this time?
Yes. At least, until next time. 
Oh, come on!..
Pretty sure we broke his phylactery thingamabob. Liches are generally dead-dead after that.
It’s been a while, but I think in naxx we did not go after his phylactery
If I remember correctly, that’s what you loot after he dies. I think maybe it was just given to someone to watch over? I honestly don’t remember. Whoever was in charge really scuffed it up, lol.
But I mean, we ARE in the land of death as we fight him in SoD. Maybe that was his ghost, haha. 
But we were in Naxx… TWICE!
How did we not break the phylactery then?
Oh, my bad. I probably vendored it and he got out again.
Doesn’t matter. 2 expansions from now, we’ll go back in time again and fight KT before he became a Lich, and it’ll be retconned that we actually created him and made him evil. Or something. I dunno. Lore is just a word now. 
Sylvanas doesn’t care about blood elves or the Horde.
She cares about the sad lava eels in the afterlife.
Won’t someone PLEASE think of the lava eels!?
Can we rejoice now? our victory isn’t a hollow one?
He won’t return with powers beyond our comprehension this time, isn’t he?
Yes, he is now fully completely dead so maybe that was Sylvanas plan along so…
Ding dong the wicked wizard’s finally dead!
LOL the WoW writers really have no idea about the lore do they? smh
Kel’thuzad was INCREDIBLY shoe-horned into the expansion.
Most covenant stories, you aren’t even aware of him, and even in the Maldraxxus one he’s barely there and not all that well explained.
This is no shade at you but it’s just hilarious that this is the one concern you had on top of the absolute convoluted spaghetti hair brained pile of nonsense and bad retcons the entirety of the Shadowlands was especially for her character. They took her character and Exodia obliterated everything about it over the course of BFA and Shadowlands.
And Zovaal was literally the absolute worst villain I have ever seen in my life.
Sometimes I wonder if this is how they think.
Nah Zovaal was okay, he just died way too easy.