Srīvidyā Paramēśvarī is depicted as seated on pañca-prētas (or pañca-brahmāsana) signifying her transcendence of these mūrti-s as well as their kr̥tyas. The pañcabrahma mūrti-s are listed thus:
निर्विशेषमपि ब्रह्म स्वस्मिन्मायाविलासतः |
ब्रह्मा विष्णुश्च रुद्रश्च ईश्वरश्च सदाशिवः |
इत्याख्यावशतः पञ्चब्रह्मरूपेण संस्थितः ||
nirviśeṣamapi brahma svasminmāyāvilāsataḥ |
brahmā viṣṇuśca rudraśca īśvaraśca sadāśivaḥ |
ityākhyāvaśataḥ pancabrahmarūpeṇa saṃsthitaḥ ||
They are: Brahmā, Viṣṇu, Rudra, īśvara and Sadāśiva.
Alternately, pañcabrahma mūrtis are listed as īśāna, Tatpuruṣa, Aghora, Vāmadēva and Sadyōjāta.
From the Vaiṣṇava perspective:
लोकानुग्रहकृद्विष्णुः सर्वदुष्टविनाशनः |
वासुदेवस्य रूपेण तथा संकर्षणेन च ||
प्रद्युम्नाख्यस्वरूपेण अनिरुद्धाख्येन च स्थितः |
नारायणस्वरूपेण पञ्चधा ह्यद्वयः स्थितः ||
lokānugrahakṛdviṣṇuḥ sarvaduṣṭavināśanaḥ |
vāsudevasya rūpeṇa tathā saṃkarṣaṇena ca ||
pradyumnākhyasvarūpeṇa aniruddhākhyena ca sthitaḥ |
nārāyaṇasvarūpeṇa pancadhā hyadvayaḥ sthitaḥ ||
The Vaiṣṇava āgamas list Vāsudēva, Saṅkarṣaṇa, Pradyumna, Aniruddha and Nārāyaṇa as the pañcabrahma mūrtis. A recent connotation of a Mantra, which gets called Parāṣōḍaśī (though it has nothing to do with the Parāṣōḍaśī of Srīkulāgama) is depicted generally as seated on these Vaiṣṇava mūrtis in medieval ritual manuals that heavily borrow from Pāñcarātrāgama, fusing concepts therein with Srīvidyā. The dhyāna of this form of Dēvī, frequently referred to as Parāśrī (signifying her origins in worship of Srī or Lakṣmī rather than Tripurā) goes – tārkṣyarūdhaharihr̥tsarōjakē, etc.
As these mūrtis are incapable of even movement when separated from sva-śakti (in the form of Vāmā etc.), they are compared to pretas (corpse). Parāmbā is described as Pañcaprētāsanāsīnā, Pañcabrahmasvarūpiṇī and Pañcaprētamañcādhiśāyinī in Rahasya Sahasranāma.
The concept of pañcaprētas is applicable to śrīcakra as worshiped by an upāsaka who has received Pādukāntā Mahāṣōḍaśī dīkṣā:
पञ्चप्रेतास्तु श्रीचक्रे षट् प्रेताः शाम्भवे मताः |
सप्तप्रेता गुह्यकाल्यां कथ्यन्ते शृणु साम्प्रतम् ||
pancapretāstu śrīcakre ṣaṭ pretāḥ śāmbhave matāḥ |
saptapretā guhyakālyāṃ kathyante śṛṇu sāmpratam ||
– The āmnāyas worshiped by such an upāsaka are five: Pūrva, Dakṣiṇa, Paścima, Uttara and ūrdhva/anuttara.
– The āvaraṇa-s worshiped are nine with the five āmnāyas worshiped across the prastāra or in the bindu-chakra (based on one’s sampradāya).
– The pretas worshiped are five: Brahmā, Viṣṇu, Rudra, īśvara and Sadāśiva.
In the case of śāmbhava-cakra worshiped by the upāsaka who is initiated into the secrets of ṣaṭ-śāmbhava krama:
– The āvaraṇas are sixteen (10+6) including the Tr̥vr̥tta chakra as Dakṣiṇāmūrti krama is the source for ṣaṭ-śāmbhava chakra. The six āvaraṇas specific to raśmi-krama are worshiped within the bindu-chakra where pramāṇa is Rudrayāmaḷa as well as ācāryōkti in Saundaryalaharī. Svatantrānanda severely disputes the idea of a practice involving saṅkalana of these raśmis in āvaraṇas other than the bindu but that discussion is quite out of scope here. However, I do take note of the fact that the use of a navātmaka maṇḍala does seem to be popular in some lineages.
– The āmnāyas here are six in number: Pūrva, Dakṣiṇa, Paścima, Uttara, ūrdhva and adhaḥ.
– The pretas worshiped are six: Brahmā, Viṣṇu, Rudra, īśvara, Sadāśiva and Hiraṇyagarbha.
A upāsaka with uttamādhikāra is eligible to worship Guhyakālī in śrīcakra after having discarded all klēśas and performed one’s own śrāddha:
– The āvaraṇas are eighteen in number.
– The āmnāyas here are seven in number: Pūrva, Dakṣiṇa, Paścima, Uttara, ūrdhva, adhaḥ and Uttīrṇa.
– The pretas worshiped are seven: Indra, Brahmā, Viṣṇu, Rudra, īśvara, Sadāśiva and Kāmēśvara Mahābhairava.
These three deities represent the three manifestations of Srīvidyā Paramēśvarī, described by Bhagavān Gauḍapādācārya as Raktā, śāmbhavī and śyāma in his Ratnasūtra.
शङ्कातङ्ककलङ्कानां दात्री तृणवदीश्वरी |
सन्धात्री बोधदुग्धस्य धात्री नः कृपयावतात् ||