Metagross: S C'mon, really? It's a wrecking ball.
Excadrill: A-
This thing works wonders. It's outstanding if you put love into training it. Even without, it's a competent sweeper.
Escavalier: B If not for its lack of speed, Escavalier would be S. However, because it lacks stellar sweeping potential, it is lower. Its bulk is still outstanding.
Zangoose: B
It's always worked for me... Facade/Slash, X-Scissor, CCombat, and Swords Dance for days. You just gotta set up first, sometimes.
Clawitzer: B- This thing packs a punch for its ease of obtaining and training. Plus, the Sphere and Pulse moves it obtains are from level up. It's not outstanding, but good for what it's worth.
Chandelure: B-
It's great, but slow. Other special attackers can outclass it, but this one's still fun to use, due to its unique and volatile typing. Pinsir/Heracross: C+ They can put in work against Luna and some against Samson, but are lackluster. Donphan: C+ Easy to obtain, easy to train, and overall good in battles. It can be great if you put in the time to breed it for more moves.
Yanmega: C+ GET IT. It takes a long time to obtain, especially with Speed Boost, but it can work well in battles without much need for support. Nidoking: C This thing can do alright. It is an alright split attacker with Sheer Force. Galvantula: C-
If only because you obtain it late-game. Plus, getting the right moves and ability can be time-consuming. It won't last long in Reborn, but puts up a good fight while it does. Aggron: D+
It's eh unless you like it. The two 4x weaknesses make it incredibly difficult to use in late-game, due to Samson & Terra.