The Moment After
Everyone would be in shock as all electronics stop. Computer users will try power on their computers. Phone users will try and restart with devices before frustratingly hitting it a couple times before sitting in a corner as they can no longer post food posts onto Instagram. Cars would veer to a stop and general chaos as the traffic lights all turn off, indicators stop working and their GPS turns off leading them to drive into the harbor. Planes engines stop and mass panic occurs as the several hundred flights left in the air all scramble to talk to the control tower before realizing they now have a very limited time to land their planes and that every other plane is in the same situation.
The lucky few people with emergency shelters enter their shelter. Before realizing that their back up generators and air pumps have stopped functioning. The president of the United states is escorted to a secure room before he realizes he can no longer tweet about it. In anger he presses his big red shiny button but nothing happens since all electricity is gone.
A Couple Minutes Later
People look up and nervously ask a passing stranger, "What happened". As the conclusion that all electricity is gone, those who witness the battling of Gods, Angels and Demons flee indoors. The unfortunate people who are near other creatures suffer a horrible fate, unable to post about their literal death online before dying. People start to figure out what happened and band together into groups. They raid stores, warehouses, board up their houses like it was the zombie apocalypse.
Cue Walking Dead but with fantasy creatures instead of zombies and instead of a cure, they learn magic