Those Mages (Philosophical Mages Saga Book 1) by Caesar Who

In 2022, coronavirus keeps reaping lives and mages are immune to it. Against mage-hating human sorcerers and the civillian mobs with their anti-mage ammunition, can they win the war against homo sapiens? Their power sources are called exousias, which are the crystalized aftermath of nuclear bomb detonations. Mages are, by default of their exousias, longevous, celibate, smarter and thus superior, but their critical thinking and philosophical spirits may fail them on this survival situation...