*gasps for air*
After several weeks, I've finally caught up with the story enough to feel safe reading this thread. I have to say, as someone who has trouble doing a lot of reading in one sitting, I wish they'd space out the stories more evenly between sets instead of dumping 10 of them in the span of a month.
Anyway, I agree with the sentiment that this story had a bit of the War of the Spark problem, in that it crammed so many things in that a lot of it ended up feeling underdeveloped. (Why Kaya is here, how Tibalt defeated Valki,
Struggle for Skemfar not really happening.) Still, the worldbuilding here was great, and the story was a fun little romp through that world at least. I really liked the epilogue, personally. I'm looking forward to seeing how this Phyrexian story develops through future sets.
Regarding Kaya's powers, her initial starting powerset always included ghostforming both herself and her daggers, so I'm willing to accept that ghostforming other objects is within her reach. What I see as Kaya's limiting factor is the amount of strain her powers put on her system. Unlike most characters, we've repeatedly seen Kaya in situations where she's too drained to use her powers at the moment. Presumably she couldn't just ghostform some giant enemy because of this. (I'm also personally treating Forsaken and the Kaldheim trailer as non-canon regarding Kaya's abilities.)