thanks for the cosmic info! Although i must say, If Vishnu is Narayana, who is Brahman, is Shakti also a part of Narayana?
nArAyaNa is not a she/he/it actually taking the literal meaning ....it is a different entity separate from jIva/atma(soul) and prakriti (nature) and which exists in everything in the universe from atom to galaxies, exists in you, me, a rock, an insect, a bird , an animal everything which has a form and name....nArAyaNa appeared as Maha Vishnu, if one were to visualize nArAyaNa, we cannot but in a form we can visualize as Sri Maha Vishnu....
As Vishnu is only the supreme brahman/god called as 'paramaatma' , the rest all fall into the jIva category,
Vishnu alone will be there at one point when nothing would be there, he keeps all the jIvas and prakriti in their subtler forms inside him and he alone exists before creation.
well creation is not a term accepted by vedic terminology because creation something that comes out new. But sristi, the sanskrit term explains, that which comes out from something......
when Vishnu starts of bringing out the universe, then just as a plant comes out from seed in multiple phases, the sristi happens in multiple phases which i would not go into taking into consideration the complexity of the process and with my little knowledge i could not take that vast subject, so anyway depending on the karmic burden each jIva carries they are placed in some physical body....some become devatas because their karma is on a higher level, but they cannot attain moksham/liberation from their places, they have to again be born as humans to attain release from cycles of birth and death.
and this sristi and layam(again entire universe will be kept inside maha vishnu in subtler form just like we keep terabytes of data inside a HDD , its not destruction..) happens in cycles.....and when jIvas are given suitable bodies, he himself again comes inside the physical body along with jIva to give him the energy to perform tasks, you need to may be explore on what jIva/atma is as mentioned in BG before it all makes sense.....the basics takes time, anyway so to answer your question shakti and Siva are also jIvas and they too go down when the layam or not apt term destruction of universe happens and Vishnu again initiate the cycle after some time and then again the same pattern will follow for some part.....but the one who got liberated or attained moksham need not go into this cycle of creation and destruction because he is allocated a separate eternal place because he desired for brahman(eternal thing) and placed in eternal place called 'nitya vibhooti' or vaikuntam or parama padam(technical terms)
Sri Maha Lakshmi as the consort of Maha Vishnu reduces the independence of Maha Vishnu for the sinners like me.... She always has to remain with Maha Vishnu, she says just like sita maa said in Ramayanam, 'those who are born in earth, show me one who did not make even a single mistake?' she tells to hanuman in Lanka, this is because according to vedas, earth/prithvi is one of the element of the body and its very nature is it gives three qualities, sattvam, rajasa, taamasa, mix of three which when the jIva occupies a physical body due to its effects and due to his false identification with physical body does mistakes....Asking these sort of question she reduces unbridled independence of maha vishnu in looking at all the sins of jIva and she covers them, that is her role and most important one....