The man who would become Mahapralaya grew in a world of poverty, abuse, shame, and neglect, leading to a nihilistic view that he carried with him into adulthood.
Taking his name from an ancient Hindu theory about the ultimate dissolution of the universe, Mahapralaya became part of the Cult of Entropy, whose goal was to speed the world along its natural path toward atrophy and decay.
In more recent years, the Cult had dwindled away to almost nothing, but Mahapralaya and a few others refused to let go of the holy cause. Termineus met with Mahapralaya and the Cult of Entropy, informing them of the shattering of the Nexus of Realities and how they might use this to accelerate the process of decay. Mahapralaya gathered up the Cult's remaining disciples--and recruited some new ones via their website--www.putrescence.com. Mahapralaya then led the Cultists to infect themselves with an array of fatal viruses and other diseases in order to prove their faith. In order to ensure that they would be successful, they set out to destroy the one being capable of repairing the Nexus--the Man-Thing. Presumably from Termineus they also learned one of the Nexus fragments had lodged itself within Howard the Duck. The Entropists captured Howard and planned to--at the moment of proper celestial alignment--cut the fragment form him and destroy it, leaving the Nexus incomplete for all eternity. With Howard the Duck in hand, Mahapralaya and the Entropists traveled into the swamp, encountering the Man-Thing and Ellen Brandt.
The Entropists blasted the Man-Thing into pieces, and Ellen fled into the swamp. When Mahapralaya left Howard the Duck to prepare for the ceremony, the Man-Thing, drawn to the Nexus power, reached into Howard's mouth and was pulled the whole way into his body. Mahapralaya returned, placed Howard an an altar in a circle of stones, and raised an ancient Mayan blade to sacrifice the fowl. However, Howard then vomited up the Man-Thing, who was embedded with the Nexus fragment and grew to immense size and power, literally becoming a Giant-Size Man-Thing. He then grabbed Mahapralaya, and the Nexus power purged him of his diseases, deformities, and pain. The Lord of the Cult of Entropy turned--a look of confusion and unexpected hope on his face--and staggered off into the swamp.