In Deadhouse Gate, Fiddler finds out who the new occupant of the throne of shadow is:
Ammanas/Shadowthrone is in fact the old emperor Kellanved and Cotillion/Rope his old companion Dancer who both were assassinated by Laseen the new empress.
It seems that the House of Shadow was unoccupied for some time (and thus probably inactive in the deck of dragons). The books start shortly after there is a new king in the House of Shadow, why does everybody know this and acts as if they know how this new ascendant usually acts right away?
Are these two ascendants in the House of Shadow always named the same and act the same as the previous ones? E.g. are they changed through the warren when they ascend?