How do I find the Dark Stars in Little Stars for Little Wars 2.0

In Little Stars for Little Wars 2.0 each "world" has 54 Crosses, 54 Void Crosses and 3 Dark Stars. However I can't find any information on even how to start attempting the 3 Dark Stars aside from the fact that they are "hidden" ... Is a way to tell at least what levels they are on?

Solution 1:

In recent update 2.1.3 the way black stars are obtained is changed. You can now see an empty yellow star above level - this indicates that in this level you can discover a black star. When obtained, icon above the level changes to full yellow star.

The way you can achieve a black star is different now. You can see a rotating star icon with a line to a single unconquered star. The star is following the path very slowly and after it reaches the unconquered star, the black star is created. Make sure you or your enemy doesn't conquere the star - otherwise the "anomally" is lost and you have to play again

Solution 2:

Found Black Stars on 2-11, 2-13, 2-16 and 6-14, 7-7, 8-18 (extra levels). Don't know how.