Evil, wickedness, ignobility. Terms that cannot be defined with empirical basis, subjective interpersonal concepts with a different definition for every folk. Some common definitions of the terms though, greed, cruelty, sadistic malaise, The Infernal though not all-in-all do seem to possess a sort-of inclination towards these behaviors; At-least prominent historical figures of their kind do leading to their unfortunate reputations. Devils causing the Great Schism, children's stories and unfortunate news articles of magickal Dwarfs in red luring folk to their death with promise of a cauldron of gold at the end of a rainbow. One would be half-witted to make blanket judgements of any folk, but when it comes to The Infernal... Many would not put it past you to at least not... fully... trust any of them, 'A Devil loves his Details' as they saying goes. But remember, just because these beings crawled from the fires of Hell, were brought into this world with a wicked sacrifice, or doomed to live a cruel existence judged for actions not their own this does not make them inherently evil, these are folk just as any other, and should be treated as-such unless you are keen to gamble how 'evil' those you offend may truly be.