Not the easiest request ever, buuuuut I'd say you go get Gallade/Mienshao, Staraptor/Archeops, Empoleon and Roserade/Liligant/Gogoat/Gourgeist/Leavanny. Recommendable sets (in my book), in order, would be: -Gallade, Steadfast, Adamant/Jolly Leaf Blade, Night Slash, Psycho Cut, Close Combat. Give it a Scope Lens from the O.Dept Store and all but the last move will crit 50% of the time. You can also give it Trick Room, which is always a plus in my book (just don't make it Jolly then). -Mienshao, Reckless/Regenerator, Jolly, High Jump Kick, Bounce, Knock Off, Poison Jab. No need to say anything here, except for the fact that you have to go back to E12 or earlier for it and once there breed it with a Farfetch'd. Staraptot, Reckless, Jolly, Brave Bird, Double-Edge, Close Combat, Endeavor. Raw power. Give this thing a _blank_ gem and any foe in front of it will be decimated. -Archeops, Defeatist, Jolly, Acrobatics, Rock Slide, Dragon Claw/Earthquake/U-Turn/Crunch, Endeavor. Jolly, not Adamant. See, Defeatist ruin offences, but not it's Speed, so Endeavor can be used to let you keep on fighting. EQ is gotten from Wooper>Corsola>Archen. -Empoleon, Defiant, Quiet/Brave, Scald, Ice Beam, Agility, Drill Pecl. Just look at this guy's stats. Speed is the only thing it lacks, but then there's Agility, letting it outspeed any unboosted foe. Panpour>Buizel>Remoraid>Piplup nets it, in order, Scald+Ice Beam+Agility along with level-up Drill Peck, to give it perfect neutral coverage. -Roserade, Technician, Timid, Giga Drain, Sludge Bomb, Extrasensory, HP Fire. The chain for SB and ES is Grimer>Stunfisk>Wooper>Mauwile>Roselia>Exeggcute>Roselia. -Gogoat, Sap Sipper, Adamant/Jolly, Horn Leech/Leaf Blade, Earthquake/Brick Break/Aerial Ace, Bulk Up. You just buff your defense and attack while healing with items when needed and start sweeping. It's pretty damn bulky, so setting up on any not-super-effective attacks shouldn't be that tough, especially if it's a physical attacker we're talking about. -Liligant, Own Tempo, Timid/Modest, Sleep Powder, Quiver Dance, HP Rock, Petal Dance/Energy Ball. Just set up a QD or 2 and you're good to go, SP helps you set that up. PD is the best STAB Grass move it gets and it doesn't even confuse it due to Own Tempo, but EBall doesn't lock you into a move. HP Rock hits all of Grass' weaknesses except for Poison. --Gourgeist, Frisk, Sassy/Relaxed, Protect, Leech Seed, Will-o-Wisp, Phantom Force. I dub it "Death by Status". LS and WoW damage the foe for 1/4 of their health every turn while Protect+PF let the foe hit you only once every 3 turns. The foe gets to ht you once while they're losing 75% of their health. LS gets it health, WoW weakens physical hits and it has great bulk (only super-sized is in the game)which lets it set up LS and WoW with ease, so it'll be nigh impossible to kill unless the foe has a SE special attack. -Leavanny, Overcoat/Swarm, Jolly, X-Scissor, Leaf Blade, Sticky Web, Slash/Entrainment. Slash is an extra attack, while Entrainment handles serious threats such as Medicham.
Whoops, forgot to add: Gourgy gets Protect and Will-o-Wisp from Yamask in E12. Sorry 'bout that.