Merrick, a Carbink among Diancie’s foremost attendants in the subterranean Diamond Domain, shares leadership of the royal retinue with Bort, Allotrope, and Dace. Despite his diminutive size, he commands authority, frequently guiding Bort and Allotrope in missions to safeguard or retrieve Diancie. Charged with escorting the princess and ensuring her dedication to critical duties—such as sustaining the realm’s Heart Diamond—he balances vigilance with exasperation when Diancie evades her obligations. Her impulsive ventures into human cities or insistence on aiding a trapped Pangoro amid danger test his patience, particularly as the Heart Diamond’s decay demands urgency.

Merrick’s loyalty remains resolute even in crisis. He intercepts attacks from foes like Riot’s Greninja, shielding Diancie at personal cost, and stands beside her until Yveltal’s Oblivion Wing petrifies him, Bort, and Allotrope in Allearth Forest. Restored by Xerneas’s Fairy Aura, he witnesses Diancie’s triumph in forging a new Heart Diamond, fulfilling their shared purpose.

Telepathic by nature—unlike Bort and Allotrope—Merrick bridges duty and devotion, having nurtured Diancie since her youth. His mentorship wavers between stern reproach and quiet pride, evident when he admonishes her initial recklessness yet softens upon recognizing her growth. This duality underscores his role as both guardian and guide, his history intertwined with the Diamond Domain’s fate across pivotal moments in its chronicle, from Diancie’s fragile beginnings to her ascendance as a ruler.