>>96229479
Maybe it would be a somewhat even fight that makes both sides look cool. Have you imagined that? Why must it be infantile shitflinging?

>valdor returns with a party made up of radical inquisitors and uses his authority to enter the throneroom
>starts doing horrible ritual thats draining the life force of millions of humans across the galaxy on prepared worlds
>gray knights outnumber custodes
>gray knights do a ritual to teleport directly into the inner palace, this teleportation ritual claims the lives of some of their psykers just to pull off such a long distance teleport from Saturn to Terra
>initially have some forward progress trading casualties for casualties against the Custodes with the weight of numbers and the advantage of psychic powers
>breach the throneroom where radical inquisition inquisitors, valdor and arik taranis are reincarnating the emperor into a new host body
>custodes reinforcements arive with sister of silence
>blanks begin to suppress the GK only advantage in their psychic powers, and the rear guard is cut down
>the grandmaster conclave engages valdor and his allies
>the custodes are like "oh not again, we cannot fail again" and are cutting down GK in swaths, but in they are also taking casualties because their lives mean nothing compared to reaching the throne room
>custodes finally break into the room as Valdor spears the last remaining Grandmaster
>custodes have to decide whether to allow Valdor to continue his ritual
>the dying Grandmaster beseeches whoever the main Custodes character to prevent the ritual, for it will doom humanity to transformation into something new and terrible and basically hints that it will make the setting like Age of Sigmar
>custodes rightfully hates Age of Shitmar and the custodes engage Valdor and manage to stop the ritual at great cost
>maybe Draigo shows up to help defeat Valdor
>story ends with the GK being rebuilt from almost nothing and reaffirming Malcadors vision of the Imperium