Castle Azure (天界の城 Tenkai no Shiro) or the Kaizerswerth (カイザースヴェルト ) as called as its true form, is the Investiture Beings' main base of operation. The fortress is based off the most powerful species for holding immense power and levitating the castle up in the sky by powerful magic.
Part of the castle also resembles a justice scale which tips when the majority of all votes are crossed.