I saw a bit of them at the final season of Star Trek Deep Space Nine, but it was clear the serie run out of time, I look some clips of Star Trek Discovery but I didn’t like the first episode of the series, so, were can find more information of them? I’m curious about this faction, specially because I want to know how strong they are compared to Jam Hadar or The Borg.
As far I understand, they are like Star Wars mandalorian, they are basically bounty hunters or mercenaries, right?
If you want to know about the Breen the only canon resource is DS9 and Discovery season 5.
EDIT: As others mentioned, also Lower Decks!
There has to be some tiny bit of Breen in Lower Decks somewhere.
I saw it, they were in a remote planet for years after the Dominion War, something who make me more curious about the Breen.
S3, ep 9 “Trusted Sources”
The crew of the Cerritos is performing their duties during “Project Swing-by” and upon checking in on the planet of Brekka, who had a drug-dealer like relationship with the Ornarans (TNG s1e22, Symbiosis), discover the population is almost non-existent, and the only lead are the Breen, who ambush the crew and Brekkian civilians.