I think the emperor himself took a ride on the seer light show.
The seer may for the most part have done things as a show but I do think she has latent abilities, at the very least, and the ritual was done right, so the emperor still having some unfinished business took the chance.
I don't really have any proof, but I still want to disagree.
There too many coincidences here:
- Sakura, possibly the last living person who can read dragonscript, was lured into palace.
- The Emperor died without naming successor and now is demanding the jade seal to be found.
- Someone reanimated the corpse of the last known owner of the said seal.
Something is telling me the purpose of this 4d chess game is the jade seal itself, possibly because it's not just pretty trinket but powerful artifact, used for other things than to make marks on paper. Which reminds me, Sakura needed sacred treasure of Adaar royal family to summon Marebito....
