In order to enter Deadman's Shadow, the leader of your crew needs to be 10.0 CL or higher.
I suggest you join a "Reg" crew if you want to DMS, since it is nearly impossible to solo DMS as a 10.0.
Crews will ask that you have most, if not all 40 zOMG! rings and all of them are at 10.0 CL.
Your ringset will be something like: Hack, Slash, Mantis, Shuriken, 2 Buffs (which will be assigned), Meat, and Fitness/Integrity/Fortune's Favor
(If you don't have some of those attacks, you can use Solar Rays, Bump, or Hotfoot to substitute)
Taking AoE (Area of Effect) attacks like Fire Rain, Dervish, Hornet, or Heavy Water Balloon is discouraged and if you attempt to take any of those, your crew will probably kick you ^^;
Good Luck!