JD...dont use Hidden power on a Metagross, even in R/S/E use something like this...
Metagross @ Choice Band (I love that thing...) / Leftovers
Adamant Nature
Clear Body
252 Attack | 200 HP | 58 Special Defense
-Meteor Mash
-Earthquake
-Explosion
-Rock Slide / Brick Break / Calm Mind
Okay, here we go. Meteor Mash is stab, and Quake is for those ghey fire types. Explosion kills.......everything. Now, here's where your item schoce and last slot come in. If you use a CB, you want to use Rock slide/Brick Break or else Skarm walls you. Now, if you want Meta to be more of a tank, I suggest using Calm mind to help raise its Sp. Defense to help sponge some physical hits..
Also you are aware that Espeon sucks, right?