i have an idea regarding Troll and White Wolf achievements
I found a text saying that Trolls myths made their first appearance in the 12th century. The account of historical figure, Bragi, a 9th century Viking poet, tells of his discovery of a troll woman deep down in the forest. ( http://oriceran.com/folklore-and-fiction-how-trolls-became-a-common-fantasy-creature/ )
Bragi, a Viking poet ... yes, but also an Aesir, well known in this game.
Following the legend, Bragi was husband of Idunn, another Aesir of War of Clans
To activate Troll secret requirement, maybe we have to activate alternaly Aesir and Idunn several times ?
2. White Wolf
Plarium makes often reference to fantasy movies and books, for example "Tibboh"; another secret achievement, is probably an inverted "Hobbit"
Let's go to Game of Thrones : The white wolf is adopted by Jon Snow, who calls him "Ghost"
So, Ghost & Invaders, Jon Snow, Snowiking ... has this achievement something to do with the Swowiking ???
Just my reflexions .. don't kill me if you find i'm stupid
Thorkildson, member of Ao7 Clan