1: [Attunement Structure]
The Attunement Structure is crafted from the biological material of the Workshop itself, and uses special resonance with Shards to communicate with the alternate reality of the Mirror Islands, which are brimming with Ethereal Elemental energies. Cooperative critters called Meebs are recruited to 'attune themselves' to the energy of a given Mirror Island, and to pass off that attunement to aid in the creation of new Ethereal hybrids via Synthesis. Take care: the Structure's resonance with each of the Mirror Islands varies from day to day, so some energies are more costly to collect at certain times than others.
2: [Rarefied Attunement Structure]
The Attunement Structure has undergone an upgrade that allows it to not only continue its duty of attuning Meebs with Elemental energies, but to actively 'Tune Up' the very Monsters of the Workshop themselves into Rarethereal forms! This process has more in common with the radical, fast-paced transformations of Amber or Wublin Islands than it does with the slower- paced, natural development of Rares as a result of environmental pressures or other factors. The enigmatic biological entity housed within the Structure's "pouch' works to target specific gene expressions of a Monster's Elemental make-up and 'Rarefy' them; as a result, Rarethereals produced in this manner tend to have a stronger spiritual presence than others.