Reincarnation is a funny thing. There is a strong implication that the number of souls in Creation is fixed and they are constantly cycled through Creation.
Stop and think about that, now think about what happened during the Contagion. Nine tenths of the Worlds population died, and most stayed in the Underworld. What happened next? Creation shrank. We know that men on the face of the world keep the boundaries strong and Creation stable against the encroaching Wyld.
Now, look at the Deathlords. Look at the magical material forged in the Underworld. Soulsteel. Steel forged of souls. Souls forever locked out of reincarnations cycle. Souls who will never walk creation again. Souls who have been ripped out of the bastion walls against the Wyld.
The population of the Underworld is growing, the dead are not entering Lethe, but growing strong on the offerings of their descendants. Eventually there will be too few souls to stand upon Creation and all will fall before the teeth of the Wyld, shattering the link to the Underworld and setting it free to finish falling into Oblivion. Or so the Malfeans plan.
Solars have a tricky job, in this Chronicle they should probably be trying to get the Celestial Bureaucracy up and running again along with reminding people of the way they should act. Foiling an Abyssal circles plots is a good way to get them started on things. Breaking up Ancestor Cults and shrinking Shadowlands would be key elements.
The Immaculate Order is the primary foil for this plan, as they are utterly opposed to Ancestor worship. If they can stamp it out and push the Immaculate philosophy back into the mind of *all* of Creation and the Underworld, they have a chance to erode the Deathlords power base. And unless they can destroy the Deathlords, they will need constant vigilance to prevent them rebuilding it over the centuries to come.
The obvious one. Go out there, take souls for your master's armoury and persuade as many as possible that reincarnation is a fools game.
Ronin might catch glimpses of the fate to come, but the Great Curse should strike the Siddies. Any who try to raise this plot in open session are likely to be mollified by any others. Doesn't stop them passing their concerns onto any other Exalts or Gods of course...
Again, preventing Ancestor worship and persuading people that reincaranation is the best option works. Lunars will need an awful lot of pushing though and without the direction of a Mentor or other allies, they may not be able to get the right handle on things.