D6

1. Lizard-folk atop dinosaurs worshiping dragons.
2. Ghouls led by the White Handed Ghoul King  and his Ravenous Knights.
3. Slave-owning Melnibonean-inspired elves, sick of human filth.
4. Beholders leading humanoid eye-cultists, covered in eye-tumors.
5. Skeletons who put bones together into frightening sentient war engines seeming to have no leader, operating more like a fungal growth made of bones.
6. Quaggoth hordes, having awoken their slumbering Cave-Bear Pantheon, with all they have taken from the recently razed Drow civilization at their disposal.

D4

1. That attack is happening right now. War is upon us!
2. We are securing the final victory after several decisive battles but tattered remnants of that invasion are still around.
3. That war is ten years done but they were hear for decades, so scars and monuments still stand.
4. They are occupying our lands and gathering the final surrendering governments.