Infernal Contract (冥契約; mei-keiyaku) is a family introduced in BS65, possessed exclusively by the Contract card, The Infernal Partner, Camus, and the Blood Crystal family cards with Contract Advent that support Camus.
Considering that the major Contract Advent cards and supporting cards of Camus are in the family, Infernal Lord, the name, "Infernal Contract", most probably comes from that.
Cards in the family are either Contract Advent forms of Camus herself, or Spirits that Camus got affiliated with in her school and on her journey traveling around Lecoulis together with Toa and the others.
