First, how exactly do I know when to use the monsters that have been "set-aside" for Shub? I'm assuming I use the Dark Young and Goat Spawns to spawn on Cultists during reckoning, but how about the Ghouls? I don't see what mechanism allows them to enter the board. And when the Dark Young and Goat Spawns are killed by investigators, do they go to the cup or do they get "set aside" again?
Lastly, every reckoning I also spawn an additional random monster thanks to Shub and advance the Doom counter by 2 if there are already 10 or more monsters on the board. Doesn't this mean with some mythos cards the doom track might advance 3 or even 4 spaces in a turn (due to omen and gates + reckoning) ?