Here's one of my favorites:

Katana V
Metamorpho V + Passenger + Armor Piercing

Most people never see this one coming, especially if you're playing a theme team.

Start them adjacent to each other and move them up a few squares on the first turn. Clear on your second turn. Wait for an opponent to move one of his heavy hitters out, preferably someone without Leap/Climb or Phasing. Use Metamorpho to carry Katana and set them down both adjacent to the oppent's figure. If possible, use positioning and Katana's Batman TA to block line of fire from your opponent's other pieces. After taking a click for Passenger, Metamorpho will now be on his best click: Plasticity, Poison, 17 Def and 4 Damage. Katana is also sitting adjacent ready to attack with Exploit Weakness on the next turn. Your opponent now has to make a hard choice - 1) they can clear and get poisoned with Armor Piercing on the next turn, as well as take attacks from Metamorpho and Katana or 2) push to try to break away, which is going to be very difficult due to Plasticity or (3) Push to attack your 17 defenses and hope to hit at least one of them, but still have to face a counter attack from the one that they didn't choose. In most cases they will try to attack Metamorpho beacuse of his high damage and Poison. If he gets hit it's ok because he can take it. He'll probably land back on one of his phasing clicks if that happens. On your next turn attack with Katana, who is clear. Now you have the option of running. You can choose to leave Katana there to tie up your opponent and take another swipe on your next turn, or take Katana with you via Passenger. Metamorpho will take 2 clicks if he does this - one for the push and one for Passenger, but it will land him on one of his two Regeneration clicks and allow you to protect him in your back row and possibly heal him back up. If done right, you can deal up to six clicks to a brick with Impervious or Invulnerability on one turn, or at the very least tie him up with a cheap and dangerous character. I've had a lot of luck with this strategy.

Just for kicks, here is my whole Outsiders team, which has a really good synergy.

Batman (starter) 47
Katana V 52
Metamorpho V 80 + Passenger 5 + Armor Piercing 10
Geo-Force E 113 (don't forget to pick up the Desk, to give him an 18 defense)
Black Lightning V 88

395 pts with some left over for a cheap feat or pogs

Nice strat. That would work with Cloak and Dagger too.

My favorite thematic combo is DangerGirl, with Abbey Chase, Natalia Kassle and Sydney Savage. That's pretty thematic.

Oh, oops... wrong idea.

for 16 pts more, you can give Protected to Katana and Entangle to Metamorpho.

I like the Katana piece, but am weary of that naked 17 DV. And Metamorpho is just a huge action-eater with the Entangle card on top of it. Of course, it only works with CC attacks, but it is a great card.

For 10 points more you can add damage shield onto Metamorpho, so if he does manage to knock metamorpho off of poison, he's still taking a click of feedback. Nasty!