The basic premise of a supervillain team is, essentially, and inversion of the superhero team. Individual villains are powerful. working together, they should be even more powerful. In practice, however, villain teams are often less effective then the villains were individually.

There are many reasons for this, but the biggest problem, I think, is that unlike heroes, the villains do not trust each other and will not co-operate with each other. It's just a bunch of individualists, who happen to be fighting in the same room.

One way to counter that might be to form a team of villains who actually like each other, and are used to partnering up. If I were going to form a supervillain team in the DC Universe, I would look toward classic villain team-ups, and recruit villains who are used to working together, for example. . .

Brainiac and Luthor

Luthor and Joker

Joker, Penguin, and Riddler

Cavalier and Killer Moth

Professor Tomorrow and Professor Ivo

Sportsmaster and Huntress

Prankster and Toyman

I was inspired to think of this while reading some of the Earth-3 stories, and seeing what a great team the heroic Brainiac and Luthor make. Of course, this is becasue the evil versions of them are also a classic team. The same goes for the heroic Luthor and the Clown (counterpart of the Joker).

The mistake villains usually make is they form a team of the heroes' arch-enemies, or at least hunt up the most powerful rogues in their rogues gallery. But these people are usually not team-players. In the same way, if I was stranded on Earth-3, and I wanted to make a superhero team, I would not necessarily hunt down the good counterparts of all the most powerful heroes. Instead, I would look for good counterparts of villains I know will work well together.