Has Rhea replaced Cadmus as villain?

Yeah Season 3 definitely can't do this half season two villains thing again

David Harewood hinted that they are building up into a "war", and he said he won't say who's fighting who with who, but "Perhaps the enemy of my enemy is my friend".

I would assume what he hinted at was Cadmus and the DEO will get into a temporary alliance against the Daxamites (and even more possibly President Marsden, who Lynda Carter reportedly confirmed that her character is a Durlan, will join in the fight against Rhea).

Whatever in Lex Luthor's box could be important (to defeat Rhea?). The DEO should just stock up on lead bullets...

Perhaps Cadmus is the really big unpleasant group, like Brainiac and Luthor in facing Superman. They just keep losing, but never lose.

It's a possibility, I can't find it but I'm sure I read somewhere Andrew K said that Teri was the Season 2 Big Bad, all I could find was the attached eonline article from Feb 1 which stated "Hatcher's role is being kept under wraps, but E! News has learned she's poised to become Supergirl's (Melissa Benoist) big bad".

The ending of Episode 17 certainly suggests she will be the big bad for the remainder of the season. She may work with Cadmus though and who knows what The President is up to.

Would be strange if we don't see Cadmus again this season given that story-line has run through Season 2 so far.