I've been using Carbink a fair bit as a utility 'mon/defensive pivot, running a very similar set to the Suicide Lead. However, I feel that is denying Carbink's impressive survivability, particularly with proper support. With its low base HP, Carbink makes a great recipient of Wishes from clerics like Florges, allowing it to come in and set up Screens multiple times throughout the game. As long as you keep it away from steel and EQ, Carbink will serve you well, and repeatedly, changing the outcome of the match.
Carbink @ Light Clay
Impish (or Careful) Nature
252HP/252Def (or 252SpDef)/4Att
- Stealth Rock
- Reflect
- Light Screen
- Rock Tomb
Depending on the situation, you can come in and rocks/screen up, or, if you suspect a switch, use Rock Tomb to hinder their speed before switching to a counter. It makes a good lead, but if you get up rocks and screens without it getting knocked out, saving Carbink for later in the game can turn matches around with a well placed screen or speed drop. If he's about to get knocked out and you know it, a final Rock Tomb serves as a fantastic middle finger to setup sweepers.
Personally, I run this little guy alongside Florges with the Impish set; she can shrug off any Scalds that might be sent Carbink's way, and can provide Aromatherapy and Wish support, while Carbink can patch up her middling Defense stat with a Reflect, or totally neuter special attackers with a Light Screen (Florges already lols at special attackers, with Light Screen they'd be lucky to out-damage your leftovers recovery.) However, keep Steel in mind if going this route; depending on personal preference, Blissey or Alomomola might make a more prudent option.