This concept is all about perception.
As they say what is perceived by one army as their guardian angel is perceived by the other as a demon.
Which leads us to the question what is perception?
I think its all about benefit & personal gain.
Whatever hinders you from accomplishing what you want i.e (stands as a wall in your face, prevents you from making your dream come true) that person, thing circumstance, ..etc.
Becomes your own personal demon.
A simple example if you build a dam on a river
A) People in location “A” are happy because the flood used to destroy their homes.
B) People in location “B” are further down the stream of the river so now there isn’t enough water reaching them. Now they are subject to Drought.
Same action two entirely different reactions.
Which brings us to the concept of something being absolute.
Aside from the villains in movies who laugh that evil laugh no one is 100% evil. Aside from the devil..
Its just a blend of circumstances, conflict of interest & a lot of selfishness.
ex1: Rich countries throw their crops in the sea so prices won’t drop whereas people in poor countries die from hunger.
ex2: People suffer from obesity in rich countries while they suffer from dehydration & famine in Africa.
Its all relative…
Depends which side you’re looking from.
The same old glass of water half empty or half full.