What does the “hero of the village” enchantment do in Minecraft (you get it by defeating a raid)?
2 Answers
Pillagers are hostile mobs that set out killing villagers.
As such, defeating a raid is directly saving the villagers, and thus a hero of the village effect is activated, giving cheaper trades for any village while it lasts
Level I Hero of the Village decreases the cost of the first item in a trade by 30%; each additional level decreases the price by an additional 1⁄16 (6.25%), up to the 55% discount with a level V Hero of the Village. No matter how large the discount is, the final item count in the trade is always at least one, never zero.
Source:Official Minecraft Wiki.
Also in java, this effect applies to all villages whereas in bedrock only the one you saved from the raid.
It makes villagers in the village give you better trades because you successfully defended them from a raid.