Hindus; What is the spiritual reason of a Yoga Narasimha behind a Sudarsana Chakra Moorti Statue in Temples?

1) Sri Sudarsana and Yoga Narasimha (From Sri Narayana Dasan's Blog):

Tantric texts are based on the doctrine that the body is identical to the universe. Vishnu is seen as the supreme purusha who has no beginning or end and is both with a form and formless. Lakshmi becomes the moola prakriti or shakti of Vishnu. Purusha (Vishnu) and Prakriti (LakshmI) are inseparable and their union lead to creation of the universe.

Lakshmi Tantram describes an expansion of Lakshmi (Sri) in the form of Agni and calls it kriya shakti and mentions that Sudarsahana manifests from this kriya shkati of ‘Sri’. Laksmi tantram also says that this form of kriya shakti: as Sudarshana creates, protects and destroys this universe. Creation begins when the kriya shakti of ‘Sri’ merges with ‘Purusha’. So the form of Sudarshana chakra with Narasimha behind maybe seen as a form of Narasimha (purusha) with the ‘Sri’ shakti to jointly take the form of Lakshmi Narasimha. Lakshmi and Vishnu are inseparable and creation may be visualized as none other than Sudarshana Narasimha or Lakshmi Narasimha.

For the tantric aspirant, the six corners may denote six chakras in ones body. Further Yoga Narasimha seated on a serpant may signify the Kundalini energy existing as a coil within us. As the Kundalini energy rises across the chakras, one progresses spiritually till moksham is reached.

2) Sri Sudarsana and Yoga Narasimha (From Ahirbudhnya Samhita):

Sri Sudarsana Maha yantram with Sri Sudarsana Murti at the front and Sri Yoga Narasimhar at the back are to be made based on Ahirbudhnya Samhita.

Ahirbudhnya Samhita of the Panjaratra Agama Volume 1:

Yoganarasimha:

tanmadhye yoganrsimhalekhanam

tanmadhye yogapattena pinaddhaggam sanatanam |

narasimham caturbahum catuscakradharam param || 26-62 ||

samasinam asokasya mule kalanaladyutim |

sarvabharana samyuktam sarvabhaktartiharinam || 26-63 ||

apara samkhya kalyana guna purnamaharnavam |

bhaktanukampinam nityam sarvalokaika nayakam || 26-64 ||

ekatra kalpita sudarsana narasimha-

manyatra kevala sudarsanamujjvalaggam | (Some text has 'kalpita' for 'kevala')

samkalpitobhayamukham ghatitastrajalam

srivisnupajjaragatam yutamantrajalam || 25-25 ||

Sudarsana Murti;

atasca bhagavan visnuscakrarupi vyavasthitaḥ |

hanyante tena cakreṇa visve daiteyadanavah || 30-16 ||

astrani tani nirjagmurviṣṇurupat sudarsanat |

amoghani tato'straṇi bhisanani mahanti ca || 30-19 ||

prajah srastum manascakre cakrarupi jagatpatiḥ |

sraṣṭumastrani sarvani svasmadrupanmahamune || 30-20 ||

(Meaning in essence: Sri Sudarsana Murti and Sri Yoga Narasimha Murti are here with dual combination. The Sudatsana Murti is in violent form with 16 hands. Sri Narasimha has four hands. Both save bhaktas from the actions of enemies, diseases and save from Graha Doshas.)

3) Iccha Shakti and Kriya Shakti;

Ahirbudhnya Samhita:

dve sakti tasya vidyete visnoh sarvarthasadhane |

pradhanabhute yabhyam tu vahatyesa jagaddhuram || 36-54 ||

eka tvicchatmika tasya tathanya tu kriyatmika |

tatreccharupinyah sakterlaksmirupatvam

prathama parama laksmirjagattratuh kutumbini || 36-55 ||

kriyarupayah sakteh sudarsanarupatvam

tattvavidbhiridaṃ proktaṃ dvitiyeha sudarsanam |

tabhyam saktibhyam vina bhagavato'pyakiṃcitkaratvam

tasmallaksmya vina devah samkalpe na prabhurharih || 36-56 ||

anenapi vina kartuṃ kiṃcinnarhati kesavah |

tasya saktidvayasya srstisthiti samharsdyupakaranatvam

anena sarvam sṛjati devo'nenaiva pati ca || 36-57 ||

(Meaning in short: Bhagavan Sriman Narayana has Iccha Shakti and Kriya Shakti. Iccha Shakti is Lakshmi. Kriya Shakti is 'sankalpa rupa unmesham'. Sriman Narayana's action in all aspects in the whole universe is Kriya Shakti. This Kriya Shakti is Sudarsana tatva. Bhagavan can not do anyhing without Lakshi. Like that Bhagavan can not do anything without Sudarsana also. Both Lakshmi and sudarsana are required for Sriman Narayana to act!)

Translations are by the answerer and they are near equal.

4) Lord Sudarshana (taken form the earlier answer):

Ahirbudhnya Samhita describes Sudarshan as the Kriya Shakti of lord Vishnu similar to Mahalaxmi. In tantras Sudarshan Chakra is personified in a form of deity. Most popularly he is worshiped in 16 hand form, where he is shown as a powerful warrier man standing posture at the center of flames emitting from blazing chakra. He is wearing red clothes, fair complexion, yellow matted hair locks emitting flames and three golden eyes. He has fanged mouth and looking wrathful.

In his sixteen hands he is holding disk, conch, noose, goad, club, axe, spear, stick, shataghni (fire emitting weapon with hundred pores), sword, Shakti (Vel a special shaped spear), bow & arrow, thunderbolt, mace, pestle and trident. In this form he is suppose to be giver of boons of victory over enemies, wealth and freedom from disease.