Maybe she talked to the ghost of Soon.
I’m guessing she was aware the Gate was located in the Azure City throne room. (She was one of the people who originally found the Gates.) Presumably, most people have heard about the fall of Azure City and the destruction of its tower; it’s probably the story of the year on Stickworld.
Sirini is enough in the know to realize that the fall of Azure City and destruction of the tower means the Gate was destroyed; otherwise Xykon would have already won. And she figured out that if the Gate was destroyed it must have been the Sapphire Guard paladins who did it. She probably doesn’t know O-Chul was personally involved.
It’s the way she’s phrasing the oaths she wants O-Chul to take. She’s being way too specific in phrasing them so that O-Chul won’t be able to make them. She’s not spitballing, she’s deliberately provoking O-Chul and could only do that if she knows exactly what happened. She’d have had to be scrying at that exact moment to know all the details, but Xykon couldn’t scry the throne room earlier.
She IS an epic level rogue who was probably involved with Soon when he constructed the chamber in the first place. Maybe she was able to work in some kind of back door.
Since the way she phrased it makes it clear she already knows exactly what happened, I can’t see how it will “turn out” that O-Chuls katana was involved in the future. The point where it “turns out” that that happened is already in the past. I think O-Chul can make that swear and still be correct.
The Scribblers took oaths not to have anything to do with each other. Now it seems that most of them didn’t take those oaths seriously, but one who did was Soon. So it’s very unlikely Soon let Serini help with his defenses.
I didn’t mean she told him she’d help out - but Soon didn’t build the castle or enchant its defenses himself, and Serini probably had a ludicrous Gather Information bonus
I see. You mean she snuck around and installed a scrying backdoor while Soon was unaware she was even in town. Yes, that might have happened.
I don’t feel that way. I feel that “I’m sure you could put my feeble little mind at ease by, say, swearing to your Twelve Gods that you are someone who would never, under any circumstances, try to destroy such a gate” is fairly generic.
If that were the only oath she proposed, I would probably agree with you. But combined with the second one, where she specifically mentions his katana and not just him, it’s obvious (at least to me) that she knows exactly what happened in the throne room. She’s trolling him, but since she’s now half-troll, I guess it can’t be helped.
You shouldn’t accuse other posters of trolling outside the pit 
Let’s make this simple: Maybe she knows exactly what happened in the Azure City throne room because she was right there, in person, watching as it happened. As evidence in favor of this proposition, I point out that nobody at all saw her there. Which is exactly what one would expect of an epic-level rogue.
Are actually all he martyrs of the Sapphire Guard accounted for? Might some of them have survived and flown to the other gate keepers to inform them of what happened?
Their oaths to protect the sapphire gate is all that bound them to this world. They’re in the celestial realm now or whatever it’s called.
Yeah, if any survived I assume they faded away at the same time Soon did (or even faster, since they were less powerful and weren’t doing anything important like talking to a disciple of their order)
If Serini’s scrying or information network is good enough to know that O’Chul destroyed the Azure City gate, it might be sufficient for her to work out the dynamics between Redcloak and Xykon. Serini might grasp that Xykon was never going to take over the world, because Redcloak’s ritual had wholly other purposes.
On other topics, Serini’s gate-protection strategy was the best, involving an architecture of misdirection combined with monitoring and active subterfuge. Its one weakness is that grandmistress Serini won’t live forever.
Nitpick: no, he didn’t. Miko destroyed the gate, like an idiot.
It was his intention to destroy it, and it was done by his sword.
Which come to think of it, is something that he himself said, in a completely unsecured location.
You make a good point. I hadn’t realized how closely her second speech matched the circumstances.
Sidenote: Any time I go back to reread an old strip, I usually end up spending an hour or more reading a hundred of them.
I agree with this 100%. And I think Burlew’s putting the memory panel there, highlighting that the details match, is meant to tell is that.