Don't use Dusknoir, there are better better Pressure stallers, like Suicune and Spiritomb.
Spiritomb has no weaknesses, and can cripple enemies with WoW, though Weezing does that. You also need a reliable counter to Mixape. I would reccomend Vaporeon. It can Wish pass, meaning you can heal other teammates, and it can beat Gyarados, AND Garchomp.
Raikou/Vaporeon/Lucario/Blissey/Weezing/???
Reccomend another Pokemon.