More Reactive Companions is one of those mods that just makes sense: it takes a huge reserve of background dialogue lines already present in Baldur's Gate 3 but exclusive to origin characters, and repurposes them as companion banter.
The fact that Baldur's Gate 3 lets you play as any of its companions instead of a custom blank slate is sick, but I think most of us are rolling with a custom Tadpoled adventurer or, better yet, the malleable Dark Urge origin.
Origin characters felt essential back in Divinity: Original Sin 2 where you had your pick of six companions but only four party slots, and whoever you didn't roll with died. With BG3's more defined class roles, expanded character creation options, and party camp for reserve buds, playing as one of those companions now feels more like a fun side thing for your third or fourth playthrough.
There's a lot of special dialogue and scenes exclusive to origin characters though—I've always been jealous of how Gale players get his talking winged cat (sorry, tressym) Tara as a companion throughout the game. More Reactive Companions takes a small bit of that exclusive content and injects it into other playthroughs, replacing incidental banter or musings from your player character with lines from your companions.
The mod's trailer does a good job of showing how it works. In a moment where your player character might toss out a fairly boilerplate summary of the Forgotten Realms' pirate city of Luskan, you'll instead hear about how much Astarion loved the nasty haven for bilge rats. Instead of your Tav remarking on a Lanceboard (fancy fantasy chess) puzzle in generic fashion, you'll get noted jock Karlach declaring how the game of kings is just not for her.
It's a nice touch, getting even more small character moments out of BG3's excellent cast. I do wonder if this might be something Larian itself tweaks in the future, though, either via patches or in a "Definitive Edition" like the developer put out for the Original Sin games. You can check out More Reactive Companions for yourself on the Baldur's Gate 3 Nexus.
