SPOILERS FOR WITCHER 3: HEARTS OF STONE AHEAD, BUT I'VE TRIED TO KEEP THEM AS VAGUE AS POSSIBLE
I've been playing nothing but Witcher 3 for the past 3 weeks or so, and recently completed the Hearts of Stone expansion. Through one specific character I started to think of the question in the title.
See, in Witcher 3 there are two characters who pose an interesting comparison. On one hand you have the main antagonist of the main story: Eredin, a genocidal, megalomaniacal, ruthless conqueror who's willing to slaughter untold millions to achieve his goal, but is ultimately acting out of a sympathetic desperation rather than deliberate dickishness. He is a complete bastard, but you can understand why he's doing what he's doing.
On the other hand we have Gaunter O'Dimm, aka Master Mirror, from Hearts of Stone and... well, to explain his identity is a spoiler, but the short, non-spoiler version is that he is capable of a great deal, and up to no good.
While both these characters commit horrible deeds, their motivations and scale differ vastly. As mentioned, Eredin is ultimately taking a "can't make an omelette without breaking a few eggs" approach that leads to slaughter on an unimaginable scale, while O'Dimm seems to act out of pure malice and capriciousness, but focuses only on individuals at a time, thus limiting the amount of misery he's bringing to the world.
Who is more evil in this case? Do we look at the end result or what these characters sought from the start? Remember, Eredin is clearly a villain, he's not slaughtering innocents by accident, but neither is he deliberately seeking them out out of sadism. He seems them as obstacles on his path nothing more. O'Dimm, by comparison, is deliberately seeking to cause misery and fuck people over.
Another comparison like this would be Griffith and Wyald from Berserk:
Widely considered to be the most evil character in the series, or at least holding the record for the worst thing to have been committed in it. But since his return to the physical world, his presence has been nothing but a boon on humanity, and his part of the story is nothing but an endless parade of heroic rescues and noble liberation. So far, anyway. Everyone is assuming his ultimate motivation can't be good, but his main goal from the beginning of the series (getting his own kingdom) has been achieved, and the point which the story is at now he seems nothing but a kind, wise and good ruler.
As you might guess from his creep-tastic stare in that picture, this guy is nothing but a piece of shit. A completely rotten,
irredeemable, reprehensible socio-and psychopath with no moral compass, no capacity of empathy, and no other goal in life except pillaging, raping and pleasure at the expense of others. But since his ambitions are limited, so is his capacity for evil. This guy will never lead a genocide or a tyrannical kingdom with an iron fist.
Here we have another case of intent vs. action. One has the capacity, and demonstrated willingness, to cause suffering on a massive scale, but seems to be acting ultimately out of noble motivations, while the other has nothing behind the surface but malice, but is limited in his capacity for acting it out.
Discuss!
I've been playing nothing but Witcher 3 for the past 3 weeks or so, and recently completed the Hearts of Stone expansion. Through one specific character I started to think of the question in the title.
See, in Witcher 3 there are two characters who pose an interesting comparison. On one hand you have the main antagonist of the main story: Eredin, a genocidal, megalomaniacal, ruthless conqueror who's willing to slaughter untold millions to achieve his goal, but is ultimately acting out of a sympathetic desperation rather than deliberate dickishness. He is a complete bastard, but you can understand why he's doing what he's doing.
Eredin
Gaunter O'Dimm

Gaunter O'Dimm

On the other hand we have Gaunter O'Dimm, aka Master Mirror, from Hearts of Stone and... well, to explain his identity is a spoiler, but the short, non-spoiler version is that he is capable of a great deal, and up to no good.
is possibly the Witcher universe's equivalent of Satan. A seemingly omnipotent, omniscient, conniving schemer who makes pacts with mortals and grants their wishes only to have them turn out horribly wrong, and reaping their souls for himself as a result.
While both these characters commit horrible deeds, their motivations and scale differ vastly. As mentioned, Eredin is ultimately taking a "can't make an omelette without breaking a few eggs" approach that leads to slaughter on an unimaginable scale, while O'Dimm seems to act out of pure malice and capriciousness, but focuses only on individuals at a time, thus limiting the amount of misery he's bringing to the world.
Who is more evil in this case? Do we look at the end result or what these characters sought from the start? Remember, Eredin is clearly a villain, he's not slaughtering innocents by accident, but neither is he deliberately seeking them out out of sadism. He seems them as obstacles on his path nothing more. O'Dimm, by comparison, is deliberately seeking to cause misery and fuck people over.
Another comparison like this would be Griffith and Wyald from Berserk:

Widely considered to be the most evil character in the series, or at least holding the record for the worst thing to have been committed in it. But since his return to the physical world, his presence has been nothing but a boon on humanity, and his part of the story is nothing but an endless parade of heroic rescues and noble liberation. So far, anyway. Everyone is assuming his ultimate motivation can't be good, but his main goal from the beginning of the series (getting his own kingdom) has been achieved, and the point which the story is at now he seems nothing but a kind, wise and good ruler.

As you might guess from his creep-tastic stare in that picture, this guy is nothing but a piece of shit. A completely rotten,
irredeemable, reprehensible socio-and psychopath with no moral compass, no capacity of empathy, and no other goal in life except pillaging, raping and pleasure at the expense of others. But since his ambitions are limited, so is his capacity for evil. This guy will never lead a genocide or a tyrannical kingdom with an iron fist.
Discuss!