Vishnu (July 2020)

Overview

Vishnu reps almost 25k HP, has 50% evasion, true light pierce for Thunderclap, and ice pierce [weak] for Ice Age. Vishnu also takes 50% less damage from his fire weakness.
Upon receiving the first killing blow, Vishnu heals 20k HP, so using demons with skills that nullifies death prevention skills, like Guts, Susano-o A, and Skull Knight can make your way life easier.
Killing Kama would be a wise decision due to him healing everyone and applying Luster Candy every turn.