I find that Complete Power. works quite well.

Now lets be serious. It really depends on which clan you like the most. When you have chosen a clan make a deck using there high damage and power cards. Try not to have too much DR unless the DR has high power and damage as they can be a bit slow in a deathmatch.

DR = damage reducer e.g Uranus whos ability is -5 Opp Damage, Min 1.

p.s the deck i posted above is my Survivor deck not my Deathmatch deck which is why it has a lot of DR sorry if thats confusing, i only noticed just now.

Give us 1 or 2 clans that you like?

A little suggestion from me will be:
T1 FPC/Bangers
Fei, Heitachi, Zhu Tang, Kusuri, Blaaster Cr(or Chlora of too expensive), Loocio, Graff, Juicy Lord.

T1 FPC/Ulu Watu
Nanook, Gabrielle, George, Buck/Numar, Fei, Heitachi, Zhu Tang, Kusuri.

This came from the tip of my mind so it's probably not the best suggestion, but I'm sure someone posting after me will correct that or come up with a better one.

If possible: Tsubame (Or Kuei if you can't afford her), Heitachi, Kusuri, Ralph, Graff, Loocio, Blaaster Cr (Or Shogunn) and Bennie should work well. But if you want to start trying to get really high places in the DT you might like to look at some low * T2 or T1 decks like this Really good tornament T2 deck..

I suggest playing t1 DM 1st then playing t2 DM when ur fourtune grows