Indeed, the Duotian Divine Demons Great Formation requires the collection of twelve Duotian Divine Demon Flags to be set up, but the Duotian Divine Demon Formation does not, as long as there are more than two Duotian Divine Demon Flags, it can be activated. The only difference is the amount of Duotian Divine Demons Qi that is gathered.
Unlike the Duotian Divine Demons Great Formation, which can condense the Pangu True Body, the Duotian Divine Demon Formation cannot achieve such an effect. At most, it can only make the person within the formation who receives the infusion of Duotian Divine Demons Qi become stronger in physical body and greater in strength, without any enhancement in their comprehension of the Heavenly Dao.