An incarnation of Laserbeak, and condor/cyborgs for the Cosmic Era
Do not meddle in the affairs of wizards... -- Gildor, via J R R Tolkien
The first sign of the Army of the Lost are the legs. Blown off legs, hopping along wearing their military boots. And not long afterwards, the rest of the Army arrives, and the horizon from left to right is filled with the decomposing bodies, many of which carry weapons. Unless you can outrun them or fortify your position, you will soon be joining this army of the Undead.
A ghost is haunting someone with a secret-it\'s not that he murdered the person that became a ghost, it\'s that he went into hiding with a new identity to avoid being murdered, whilst the ghost wants him to join her in the afterlife. The ghost is getting stronger and more dangerous each day. Enter the PCs.