May I just say, The Cabal are one of my top 10 favourite enemy types of all time.
Just the way they're introduced, and the music that plays when you're in their territory, just fits so well.
(spoilers ahead)
Like, you start off on mars, an both you and your ghost have no idea what you're up against other than the fact that they can easily wipe out a entire
planet on their own, you go into the base, its eerily quiet inside, you deploy your ghost to try to figure out stuff about them, and suddenly the Large Metal doors open up,
This Starts playing, and suddenly a huge group of Heavily armored Mercenaries start charging at you with Jetpacks, grenade launchers and massive shields, dropships coming in dropping more of them in, until finally you kill the last few of them after a huge and long battle against these Huge Military-trained soldiers.
Pretty much every fight that you have with the cabal feels threatening, and the music definitely makes them seem like it too.
The Cabal are definitely my favourite type of enemy in this game and one of my top favourite overall.