Krishnavatara -Deification of living human was started in India by Rig-Veda- which deified 13 living humans, including War-lord Indra, who was made the top god . Vishnu was a very minor God in Rig-Veda. Much later, Vishnu was deified by Puranas, showing him as killer of Ashura Hiranyaksha, his brother Hiranyakashipu, subjugator of King Vali as a dwarf Brahmin. Parashurama, became Avatar of Vishnu, claiming that he ended all Kshariyas on Earth. Ramayana deified Rama as Avtar of Vishnu, as killer of Ravana. Krishna qualified to be the best Hindu God, killing 9 deemed Ashura in early life, later killed king Kamsa, Jarasandha, Shishupala, Shalya, Narakashura, Vanasura etc. Krishna led Pandavas in War of Kurukshetra, getting both Pandava's and Kaurabha's heirless, killing 19 Akshauhini soldiers. Finally he killed all Yadava clans, his own sons and grandsons in Prabhasa, got himself killed by a Vyadha . Rishi Vyasa made Krishna a killer-god, but by importing "Radha Character", Brahmavaivarta Purana- made Krishna a God of Love. As a Hindu, you can call any number of humans as gods, but awarding them epithet of Vrahman, as Bhagavata did on Krishna is an insultation to Upanishada, hurting people who are Vedantic Hindus. Krishna's frequent journey to Heaven and hell to bring all dead men alive, lifting a whole mountain does hurt us, a it is writer's right to create fictions. Vedantic Hindus bear the pains of inducing worship of God in any Anthropomorphic form.