I think vriska should NOT die for 'thematic finality.' It's cruel to terezi, vriska, and the rest of the originals with the unclear end. The ending involves rebirth and as Homestuck is a meta creation story, re-creation.

See, okay, I don’t want to start Vriscourse here, but let me tell you my hot take on this.

I don’t think Vriska deserves to have Terezi by her side in any capacity.

During the Lead-up Monologue to Terezi: Remem8er, Terezi mentions the good times they spent together, how they built each other up- But Terezi also mentions that her being there has not fixed her issues, obviously. There’s something more, something deeper, a doubt, a lack of confidence, that she gets, vicariously, through Vriska’s self-assured personality. This works for their mutual benefit, but as she mentions, it’s only a temporary fix.

Terezi feels incomplete, lacking substance, she regrets not remembering anything that built up her Game Over counterpart, and in the end, this leads her to needing to remember the Game Over Timeline with her Seer of Mind powers, because she needs to know her own mistakes, her own choices, how she came to the conclusion of sending John back in time to save Vriska, and on top of that, if the Flash is anything to go by, she gets to experience the catharsis of her the culmination of her relationship with Vriska. Happy, content, together.

The issue here is that (Vriska) mellowed down. She stopped chasing after being the most important character ever, and we have to look at her now alive counterpart, Vriska. She’s cruel- She mixes Tavros with something he’s allergic for, without his consent, and frames it as her making him stronger- Nay, he talks of it as REDEMPTION even, by bringing him back to life. She hijacks the Meteor and shoves everyone to a secondary plane, taking the Leadership from Karkat’s Hands and just doing what she wants. Raiding Roxy’s house, forcing the Strider Reunion, bashing her other Self for her more content, non-relevant attitude, nearly having a breakdown when Tavros turns out to be useful, Vriska is an asshole whose actions revolve entirely around making herself to be the most important character in the comic, and her ego is the size of God Damn Jupiter.

Terezi’s Moirailship feeds into this Ego, she’s so happy to not have needed to kill her, after all! But Terezi mentions, as good as their relationship is, she can also sense that Vriska thinks less of her- That she thinks of her as something Tragic, even. Their relationship isn’t one-sided by any means, but there’s not the same level of mutual reassurance, and knowing what we know of Vriska, she’s remorseless and cocky.

If Vriska comes back from the Lord English fight, she’s not going to go back to being Terezi’s Moirail the same way again. We’re going to have Terezi, having experienced GO! Terezi’s outcome, desiring what she has, but being stuck with a Vriska that’s even more egotistical than now, because she will have ‘defeated Lord English’. EVEN if somehow with these new circumstances, they came back around to their old Moirailship, we have some more context about how Terezi is using Vriska as a proxy to feel better about herself because she cannot find what’s missing for her.

The thing Terezi needs is not Vriska- It’s (Vriska), and Honestly ‘it’d be cruel to Vriska’ THAT’S THE POINT, I LOVE Vriska as a Character and I LOVE her framing with her and (Vriska) and the Pre and Post Retcon Conundrum presented with Terezi, but at this point in the story she really doesn’t deserve good things. 

Let her get exactly what she wishes by becoming the most Important Character in Homestuck- And watch that very same ‘Heroic Sacrifice’ become her undoing.

That’s my point of view on the Vriska-Terezi situation. Terezi deserves better than Egotistical, Awful Vriska, she deserves her punk, nice girlfriend.