Kess Grayson is determined to rid herself of the cryptic writing covering her body, which nobody seems to be able to understand. This is a better opening, but it sounds like her problem is that no one understands the writing, not that she woke up one day with it all over her.
Kess is a Chronicler, or was, until she broke erudite tradition and asked the Guardian warriors to train her. Can you give a hint about what Chroniclers and Guardians do and are? Now she doesn’t know who she is. She asked, breaking tradition, but does that mean she succeeded? "she doesn't know who she is" is interesting but also vague. Does this mean she doesn't see a future for herself, or she's wondering what future path to take, or what?
Thrain Storgaard, former Guardian Commander of Athenaeum this title doesn't really mean anything at this point, and just adds in more words to be explained, believes all Chroniclers are all craven fools why?, yet somehow Kess has skirted his animosity and gained his respect. how?
Despite her Guardians So she has a Guardian of her own? scepticism, Kess and her companions Who are her companions? Just something like "her best friend Bob" would help leave their Haven what? travelling to Rome in search of an Augur, a mythical being able to answer any question. What prompts this move?
Kess’s hopes that the markings will vanish are dashed when she learns that she is I wouldn't italicise this the true Book of Revelations, a guide to the Apocalypse for Heaven or Hell. Does this mean she, as a whole person, is the Book, or that she is now the Book because of the writing? Is the writing the Book? If the writing went away, would she still be the Book? What if she wrote down everything on her skin, would that change anything, now that there are two copies of the Book?
The emergence of Kess’s abilities what emergence? breaks the first seal releasing War, a Horseman of the Apocalypse and with him, a massive demonic army.
Knowing the final battle is approaching, the warriors what warriors?, led by Thrain, approach the other Havens seeking aid of their Guardians. Yet while the leaders of Bandar and Asile pledge their allegiance, things are not as they seem in Weichen at this point, these names don't mean anything where Kess is struck insensate by the Haven’s protective Obiex stone and the Guardian leader is being controlled by an outsider. There's so many fantasy words in this sentence, and it's too long.
When the Haven forces gather to contain the demonic army, Kess sacrifices herself like she dies? in the hopes of saving their outnumbered army and her companions.
But if Kess has misunderstood the translation of the writing covering her, she might be serving the darkness instead of light and breaking another seal releasing more of hells horrors upon the world. Spelling this out so directly implies that yes, this is what happens.
This is better than the first draft, but it's difficult to see a solid structure or where the plot's going. I don't think you need to mention Thrain - he doesn't appear to have much impact on the main story, and if he does then we need to see his connection to Kess more clearly. Are they lovers? Friends? Does he go with her to see the Augur? The previous draft made it sound like Kess was an ordinary normal human, but this draft makes it sound like she's already in the fantasy world, in her position as a Chronicler. What is the inciting incident that kicks off all the action? Is it the writing appearing on Kess' body or her breaking tradition and going with the Guardians? I'd start with that inciting incident and build from that and its consequences.