There are 214 Demons to track down in Shin Megami Tensei V. You can obtain Demons via Negotiation in battle or by fusing them using specific recipes. This page details the Fallen demon Decarabia, and contains information on all of its skills, stats, fusion combos and more.
One of the 72 demons of the Goetia. He usually appears as a pentagram, but can appear as a human if his summoner wishes. He excels in knowledge of ores, gems, and plants, and will teach them to his summoner.