This was cooler in my head, but there's too many humanoids. I should probably have included orcs, but I intentionally left goblins out.

You are aware as worded right now "the first group" are the non-Elf non-Human etc.? (Or more precisely, there is no "first group", but a criteria that could be used to build it.)

I don't see why you make things so hard on yourself with the many negatives, though. I think, I can suggest a better wording:

> "[if that player chose Monster] target creature that is an Azra, Dwarf, Elf, Faerie, Giant, Human, Kithkin, Kor, Merfolk, Vampire and/or Vedalken. Otherwise [...] target creature that is none of those types."

Also: It's time to introduce a singular term humanoid and move that list into the rules if you want to do stuff like that.

Also-also: Right now your wording makes it so the controller of the enchantment chooses the targets and the "each player" entity just chooses yes/no on the "may destroy".

Also-also-also: Right now this triggers each player's upkeep AND has each player make a decision to destroy each upkeep, so in an N-player game this could destroy up to N² creatures er turn cycle.

Also-also-also-also: Right now the triggered ability is worded in such a way that both targets (a "people" and a "monster" need to be targeted each time). That means if all creatures on board are e. g. Merfolk, the ability won't go on the stack for lack of targetable "monsters" even if players decided to side with monsters.

Suggested wording:

> As ~ enters the battlefield, each player chooses Society or Wilds. [List of creature types] are people.
At the beginning of each player's upkeep, that player chooses a target creature. If that creature is a people and the player chose Wilds, destroy it. If that creature is not a people and the player chose Society, destroy it.

There are more elegant ways, but I'm in a bit of a rush after taking so long to type. ^^