A mysterious heavily customized Gunpla that suddenly invaded Freddie’s mission. It departs greatly from ordinary customization rules, resulting in a strange silhouette with a massive monstrous right arm as the “Seltsam” in its name implies. Besides the huge arm that clearly unbalances it, this bizarre Gunpla also displays demonic strength that far transcend the limits of common sense. The reason for its strength that allows it to face the BUILD DiVERS alone, and the identity of its pilot are some of the mysteries surrounding the Gunpla. In any case, it is a fact that it’s the greatest threat for Hiroto Kuga and his friends.