OK here's my isekai pitch from last night after finishing Fantasy Knockout

The setup is conventional

The hero is summoned from his world into a fantasy kingdom

The goddess tells him that the demon king's seal is almost broken so he must use some as-of-yet unspecified super hero skill to gather his power and allies and prepare for the ultimate battle between good and evil

Then he's set out onto the road, captured by bandits, and sold into slavery

Shipped off into an entire city that's functionally run by a human trafficking syndicate

he then uses his Hero abilities to orchestrate a slave uprising

takes control of the city

and secures an audience with the king about it

King: "Well we don't condone the slave trade, but--"

Hero: "This entire major city was run by the slave trade"

King: "If you think about it from an economic standpoint, then--"

Hero: "I'm declaring this city an independent nation where slave trading is punishable by death"

Economic/Political/Fantasybattle conflict with the kingdom begins

Hero finds the sealed demon king

Demon King: "Are you here to stop me from exacting my revenge"

Hero: "It was about the slavery thing wasn't it"

Demon King: "Yeah"

Hero unseals the demon king and recruits him as an ally

isekai where the slavery thing comes up once and immediately becomes the focus of the entire story

because to do otherwise would be a crime against humanity