Liberating slaves and freeing slaves is a complicated business.
Slavery as it tends to exists is a powerful and pervasive institution set within a society. It's an evil practiced by ordinary men rather than supernatural beasts. Killing the landowner might be as simple as knifing a L3 commoner. Or a L4 commoner, if we're generous.
The liberator is a builder of networks like the underground railroad to get the abused out of enslaved areas. With so many vulnerables they're suddenly, directly responsible for (who are often starved and defenseless, themselves), the liberator can't afford to get caught. They operate in the middle of dangerous territory to protect groups of vulnerable people.
They may possess the defenses of a rhetorical firebrand, arguing in forums for slaves' release. They may use that rhetoric to build their railroad, convincing people on the fly to work with them.
So...their talents by necessity are more subtle, and they aren't fighting massive beasts so often, but are fighting within institutions. They are involved in search and rescue.
A liberator PrC exists; it focuses on the ability to disarm manacles, to sneak past guards and to uplift the endurance and spirits of the slaves you've freed who've been underfed, beaten, and overworked for some time.
We have a rogue PrC as well. They gain an aura effect (how cool is that?) to stealth and disguise, to get the slaves out alive. It'd be cool to combine some of these great ideas, as well as add some sort of "underground network" ability at mid/higher levels, sort of like what the Vigilante has for influence. Or some sort of "firebrand speech." :D
I know this isn't a democracy. But, hopefully we'll get some fun, and geek-laden historical perspectives in here as well.
I'd love to see it continued as a rogue, or inquisitor, archetype, but especially rogue. The rogue deserves some sparkle and prestige from concepts like this one. I think the firebrand angle could give it some pizzaz!
Anyhow, as always, thank you for reading and thank you for all the work you've done. :D