Yeah, 3 cysts for summon monster and one greater one for planar binding up to Echidna's abilities. The cysts are located in the castle but the spawned entities can appear anywhere on the castle (either on trigger or event or by will of Archfiend who touches on any part of the castle and wills it summon spawn). Archfiends are aware 'how many summons left' in per given day when they touch and access the cysts.