Just a few suggestions...
1. Medicham: I suggest Life Orb > Choice Band, mainly cause it's a pain to worry over clicking the HJK button when spiritomb fills the tier. LO still hits hard, and you can get some pseudo recovery from Drain Punch.
2. 2 SR users is pretty bad tbh. I'd suggest replacing Crustle for a typical LO Absol (you can get ballsy and maybe go for SD). It would greatly help when dealing against threats such as Specs/Scarf Moltres, Magmortar, and Typhlosion, all who utterly destroy your defensive core of steelix & Cryogonal.
3. Replace HP Fire on Mesprit and add CM/Nasty Plot, and use Leftovers, to get a great bulky sweeper.
4. You can opt to rid of Cryogonal for Lanturn/Slowking, making an extremely great core with Steelix.
5. As for a 6th pokemon, you can run Scarf Typlosion, one of the most common and arguably the most dangerous scarfed pokes in RU. If you dot want a speed tie vs other Typhlosions, then you can opt for Scarf Manectric, to Outspeed and revenge kill Typhlosion when it's weak, or just Volt Switch into Lanturn to absorb a hit and thus make Typhlosion weakened.