No soul is exclusively happy, enjoying throughout the period of it's life. There are moments in which it has to taste the miserable nature of life. Likewise, no soul is totally unhappy all through life. No individual soul is like any other soul. This is because of the Karma done by each soul in previous births. At the will of Bhagavān, the souls come in to contact with non sentient world and become enjoyers through it, according to the results of their past deeds.
Śakti brings in to the world the Manus who rule the Manvantaras, then the seven sages who are the sons of Manu and then the material world. The souls may leave the physical body on their prefixed time, which it does not know, but is fixed by Bhagavān. According to the nature of deeds, it may enter in to another physical body through which it could have the experience of the results of other past deeds. Thus, many souls have countless number of deaths to be followed by rebirths. Many souls would continue to be bound by worldly life for numberless times. Very few would take to the means of emancipation and will not return to the world. If Bhagavān were to wait till the selves get qualified for mokṣa, there will be no possibility for this and so He must bring in dissolution making the selves which are still in bondage enter the jīvakośa.
Śakti or Bhagavān exercises His or Her free will to fix a time for the creation and also for the dissolution. The Purāṇas state that Viṣṇu protects the created world. This is admitted in Pāñcarātra system also. Laya or dissolution is called by the names pralaya and pratisañcara. The knowledge is the basis for the maintenance of the world. This continues for as many times as fixed by Bhagavān.
When avidyā sets in, vidyā ceases to maintain and run the universe, with the result that only the forces of Prakṛti remains operative. It is at that time Śakti begins to withdraw the created products. The the world of sentient and non sentient beings become dried up by massive winds and burnt by ferocious fires and merges in to Mānavas (descendants of Manu). The Mānavas, who are four hundred in number merge in to Manu. Thus all sentient beings merge in to Manu. The element earth merges in to water, water in to fire, fire in to air, air in to ākāśa, ākāśa in to ahaṁkāra, ahaṁkāra in to buddhi, buddhi in to Tamas ( this Tamas is not tamo guṇa one of the three components of Prakṛti. Tamas here is the name given to avyakta/unmanifest, that is Mūla Prakṛti, in its particular subtle state. It is also called Ākāśa and denotes all things other than Parabrahman).
The sense organs merge in their causes along with the elements. Tamas (here Tamas is the quality found in Prakṛti) enters in to rajas, rajas in to sattva, sattva in to kāla/time, time in to niyati, niyati in to śakti, śakti in to kūṭastha-puruṣa ( This represents the aggregate of ātmans similar to a bee hive. Here only ātmans who are bound by karma can be found. Kūṭastha puruṣa is the all knowing Puruṣa who is the head of all puruṣas. Bound Jīvas emanate from him during creation and returns to him after dissolution. This Puruṣa manifests from Pradyumna). Kūṭastha puruṣa merges in to Aniruddha, Aniruddha in to Pradyumna, Pradyumna in to Saṁkarṣaṇa and Saṁkarṣaṇa in to Vāsudeva.
Pāñcarātras does not mention other kinds of Pralayas found in other scriptures.
🙏 Namo Narasimha 🙏