If we're using D&D terms, Arcaea strikes me as True Neutral more then evil, though Jenred has some seriously warped standards which can make it appear both very evil and very good, often at the same time. He certainly believes the ends justifies the means, often his means are Really Evil but his goals are Quite Good.
Arcachon is more Lawful Evil then anything else. I'm actually considering lifting from Ravenloft:PotM and having signs reading "If You Walk Adghar's Land, Obey Adghar's Laws." pinned to crow-cages. There are definately a lot of Chaotic Evil players in Arcachon thought and it's by and large ruled by Evil characters (current council 2 LE, 1 NE, 1CE), and one Lawful Good elf from Sirion.
The hilarious thing is that the "evil god" they are always on about in Arcachon does pretty much what they do daily. He's doing it for Evil though, which makes Arcachon Good. That is why our army is filled with crusaders and paladins, because we are good.