It seems like a fun enough team but it can be picked apart without much thought by too much common stuff:
1) Dugtrio owns more than half of the team right off the bat, highlighted by the fact that if Medicham even kills anything it goes down the next turn to a Dugtrio revenge kill. That leaves you with just DD Salamence for any real offense, and that's not enough without any other support.
2) The Skarmory+Dusclops, (actually any ghost will do) combo absolutely walls you cold, what's even worse is that with stuff like Steelix/Umbreon/Celebi/Salamence that is easy spike bait, you're going to have to do something about Spikers than just Starmie because it looks like your team does a LOT of switching.
3) The VILtar set hits everyone pretty decently but everyone on your team can hit it back hard enough as well, save for Umbreon. For that, just set up a Wish if VILtar comes in, then pass to Medicham to deal with the problem.