Shedinja @life orb
252hp/252 def/4spdef Bold
Sandstorm
Life gamble(or death gambit, whatever the translation is)
Double Edge
Substitute/Troll/Rest
best set imo.
I really advise using troll at the 4th move slot since now you are hitting from both sides of the spectrum and a 60BP move coming from a blistering 30 base SpA is really threatening as it has the power to 3HKO Kakuna (standart 0/0 HP/SDef with hindering nature since Kakuna is usually a Harden Sweeper)wich is one of the most defensive pokemon in the troll tier.
Sandstorm isn't completly useless, because while Normal/Normal Coverage is great it misses out on enemys shedinja and deals a fair 6% damage to every other ghost.
Life Gamble is great to take out all those nasty focus sash/Sturdy Pokemon that resist Sand Storm or if you just can't afford having Sand Storm on (because you don't want to cancle your magikarps lefties or to not stack the residual damage for your LO Lovedisc) .
Rest is a great option to avoid status like Burn or Toxic wich often kills you sadly it comes at the cost of not being able to do anything, but what could your opponent do? Switch? Set-Up? No, the divine terror of Shedinjas pure presence on the battle field will prevent your opponent doing this.
Double Edge is a great Option to hit even Defensive mosters like Carvanha or Pikachu for an OHKO (and you doesn't have to care about Carvanhas Rough Skin or pikachus Static because you simply die while killing them). Another great thing about Double Edge is that you don't have to care about the recoil, because Shedinja will only lose 1 HP everytime it uses it and it doesn't even take LO recoil!!! Take that game mechanics.
Overall Shedinja is a great team mate for all Sand Storm/Hail Teams that have too much space left and need something to death fodder and absorb Status, no longer thinking about who should take that incoming burn or what to send in after ScarfTars Pursuit just lean back and watch Shedinja dieing to SR, because you forgot to spin rocks away in before.