[quote=@Raineh Daze]
<Snipped quote by CorpusMundus>

All in black, faceless masks, the leader has a pointy hat, they're carrying flamethrowers, and the ominous green smoke makes them look like Disney villains. And they're unrepentantly cultists.
[/quote]

You should see their leader, a glorious, hammy, bald son of a bitch with a goatee. Though despite uniting the third world and bringing order, law, and aid to contaminated areas of Earth that were abandoned by the world leaders, he's seen as the bad guy by GDI. 

As for the cultist bit, the same can be said about Christianity and Islam, being radical Jewish/Abrahamic cults/heresies. In truth the Brotherhood also worships the same God, but aren't affiliated with the other three Abrahamic faiths and think Kane is their Messiah. Like how the Rastafarians believe that some Ethiopian Emperor was the second coming of Christ.