Claw-Abiding Citizen
Clawitzer@Life Orb
Modest/Quiet nature
Mega Launcher
252 HP/252 Sp. Atk/4 Defense
~Water Pulse
~Dark Pulse
~Dragon Pulse/Sludge Wave
~Aura Sphere
It's very easy to build a good moveset for Clawitzer. Water Pulse is your STAB of choice, thanks to Mega Launcher making it actually decent. Dark Pulse, Dragon Pulse, and Aura Sphere are all chosen for their compatibility with Mega Launcher's effect, though if Fairy-types worry you, you can replace Dragon Pulse with Sludge Wave. It won't get that sexy Mega Launcher boost, but it'll give you that extra coverage.
Item powers up Clawitzer. Ability is non-negotiable.
Other options:
*If double battles are your thing, Clawitzer is basically the best user of Heal Pulse ever thanks to Mega Launcher- yes, Mega Launcher even makes Heal Pulse work better.
*If you think Clawitzer needs even further coverage, there's Ice Beam and Shadow Ball.
*Z-Splash, Aqua Jet, Rock Slide, and Crabhammer would in theory give it something of an option for a physical set, but... yeah, no, stick to the superior attacking stat that covers all the moves that its Ability works on.
Abilities:
*Mega Launcher: Clawitzer's one and only Ability. Clawitzer's aura and pulse moves are 50% more powerful. This means that the base power of Water Pulse, Dark Pulse, Dragon Pulse, and Aura Sphere gets multiplied by 1.5. And Origin Pulse, if Clawitzer were ever to learn it, which right now it doesn't. It also makes Heal Pulse heal 75% of the target's health, rather than 50%. That's right- they thought of everything with this one. Clawitzer doesn't get any other Ability, so this is what you're stuck with, but you could do way worse than this.
Partners:
Clawitzer is slow, relies on its bulk to stay in the battle long enough to dish out hits, and can't really heal itself, so Wish support would be invaluable.
Counters:
Azumarill and Primarina can switch in with impunity, provided Clawitzer isn't running Sludge Wave. and wear it down with powerful attacks. Special walls in general give Clawitzer grief, even if they're weak to any of Clawitzer's moves-Aura Sphere may be its best option against Chansey, but that doesn't mean Clawitzer should be your go-to Chansey killer.
Opinion:
I do prefer its version-exclusive counterpart of Dragalge between the two, but credit where credit is due- Clawitzer is an awesome Pokémon in its own right.
Prediction for next week:
Gumshoos.