The Campaign Builder's Guild

My idea for the PbP Mirafar reclamaition game was that when the PCs reach the Lich at the end of the game, he would already be dead, as in not undead anymore. Before the PCs get thru the catacombs to reach the Lich King, he would have developed a spell that would create a dark and ever hungry phantom forever seeking to suck the life of all as a form of final revenge apon the world for taking everything away from him despite being the Goodest Ruler the world had ever seen. The spell would require him to infuse his spirit into it and then consume his soul as a power source, which is impossible to do alone. So he writes his last words into his diary and weaves the final magic to seal his spirit and finish the spell, then submits his soul to start the ritual.

The PCs would trigger the final spell by reading the final entry in Mirafars diary (lengthy tear jerking poem), immediately melting the Lich King's corpse into a pool of eternal darkness and summoning a horde of shadows, many of which will just leave to find easy prey like 1st level warriors in a pitched battle with planar invaders outside the necropolis.