Potential Article - Killing the Lady of Pain?

Ramifications

All the streets of Sigil resemble those of the Shattered Temple. Much of the city is in ruins, with massive cracks revealing the depths of Undersigil and the nothingness that lies beyond the now open Cage. Thousands are dead, and lying amongst the corpses are the sickening dabus, their last words floating above their weary heads in the form of grey and black rebuses. In your arms is your soon to be dead enemy, and its amazing how *light* she is in the sliced cradle of your arms. With her last bit of life force she beckons you near her. You lean in to hear what she has to whisper even as the portals of Sigil flicker with the arrival of fiends and angels and far older, more dangerous things...

It's over. Though most of your party might have died to accomplish it, the Lady of Pain is dead. What happens next? That's up to you as the GM, though you might choose to enact one of the options below.

Godswar

If the Lady of Pain is what keeps the powers out of Sigil, her demise will mean that countless gods - not to mention planar lords - from across the Multiverse will attempt to enter the City of Doors either to seize control or to keep one of their enemies from doing so. Even if the gods can't enter the Cage right away, they're servants will take to the streets to slaughter their rivals. One of the reasons for Sigil's diversity is that many powers keep their followers and creations in the Cage in case any opportunity to take over the city arises.

This war won't be limited to Sigil either - pantheons will war with one another across the planes, hoping to thin the herd of powers they're competing against. Countless artifacts and monstrous horrors will be unleashed, so that even if after the dust settles there is a god who controls the City of Door it's likely that deity will preside over a shattered wasteland of a Multiverse.

While this war of deities is going on, one place that will see an influx of planars is the Prime Material Plane. Though gods migh be able to work some miracles on the Prime, their power is greatly reduced and thus it is much, much safer to be on what the planars brashly used to refer to as "backwaters".

Note that while many gods sought to overthrow Her Serenity, there were those who likely approved of the balance she fostered or believed her to be the one legitimate ruler of Sigil. Others may have been her secret lovers or friends, and in the case of Io perhaps even her sire. Once control of Sigil is decided, many of these beings will seek out the Lady's killers in order to pass sentence or have their vengeance.

Someone Must Always Sit Upon the Throne of Blades

It is possible that the Lady, or whoever empowered her to rule Sigil, prepared for this eventuality. In this case, there might be a series of tests one must overcome in order to gain control over the Cage. Whether everyone in the Multiverse is an eligible candidate or the contest is limited either to her killers or the citizens of Sigil is something each GM must decide for themselves. It might be the case that to undergo the quest is to be pulled to the cause of the Balance, in which case by the end the new Lord or Lady of Blades has been molded into a suitable replacement for the one that was killed.

It's also possible that control of Sigil is more akin to a punishment than a reward, with ones will largely directed by the dabus or the city itself. In this case the one who dealt the killing blow might be condemned to take the place of Her Serenity until, eons from now, they too might taste the sweet release of death.

The Lock is Broken, the Play is Done

Perhaps Sigil was in fact a seal, and suddenly the death of the Lady no longer allows it to act in that capacity. This might mean something horrible emerges from the Far Realms, or it might be that the Greater Unknown of the Athar is finally free to turn the Multiverse into a Paradise.

Sigil may have been called a Cage because it kept all the Multiverse from rising to the next level of existence, or it might be the case that the Lady's death reveals the existence of parallel Great Wheels that together form the Meta-Verse. Perhaps with the Lady's death Factol Skall is free to lead the Great Wheel to the True Death, or Factol Erin is able to use the seal in the Sensate headquarters, the one that resembled the now dead Lady, and turn everyone into disembodied spirits free to gather senses from across reality without the impediment of their bodies.

Little to Nothing

The moment the Lady dies, it is possible that she vanishes and reappears floating above her would be assassins. Before the shadow falls, the reward for all their world shattering efforts is a mischievous smile playing across Her Serenity's gun metal face.

If this is to be the case, make sure that the players of your campaign received plenty of hints and warnings that their efforts would prove futile. In fact, this might be an ending better saved for a one shot, even if your campaign centered around saving the Lady rather than killing her. A pointless campaign, after all, is a pointless campaign.