@Salut168 Without wishing to be either rude or discouraging, your English whilst clear is not flawless, therefore, perhaps your perception of what does or does not constitute the correct English translation of any particular word may be mistaken. As I say, please do not read this as an insult, I would be delighted to speak Greek as well as you speak English but there are many shades of meaning in English words which are not always obvious to a non-native speaker.
Overall, I have found the course to be of high quality and it is, as I'm sure you are aware the beta version that we are currently using, the finished product will be even better.
Well if that is so, then the primary translation needs to be updated, because as of typing this message it presents itself as "vicious", which definitely does not have the same connotation as "evil/wicked".
Personally I believe that "evil" shouls be the primary translation, with the aforementioned ones left as options.
https://el.wiktionary.org/wiki/%CE%BC%CE%BF%CF%87%CE%B8%CE%B7%CF%81%CF%8C%CF%82. Maybe it's how the people in Cyprus use it? I live in mainland Greece...