Involved in the biosynthesis of a nickel-pincer cofactor ((SCS)Ni(II) pincer complex). Binds Ni(2+), and functions in nickel delivery to pyridinium-3,5-bisthiocarboxylic acid mononucleotide (P2TMN), to form the mature cofactor. Is thus probably required for the activation of nickel-pincer cofactor-dependent enzymes. Ni(II)-pyridinium-3,5-bisthiocarboxylate mononucleotide = Ni(2+) + pyridinium-3,5-bisthiocarboxylate mononucleotide Belongs to the LarC family.