Maybe the name itself should give a clue. Like Akass is formed of aka ss (aka: also known as)
It's been a long time in coming, but as yet another post I have come across in doing some forum house-keeping raises a point that can be usefully answered, it's got to be said that this was not the route Hergé was taking with the name Endaddine Akass
Referring once again to the invaluable book, Tintin: Ketje de Bruxelles
, by Daniel Justens abd Alain Préaux, they trace the name to being yet another example of Hergé hiding Brussels slang in his naming of people and places.
The expression "en dat in uw kas"/ "en dat in a kas" (literally meaning something like: "...and that's in your face!") appears to convey the same sense as "...and you can put that in your pipe and smoke it!" in English, in that it is a phrase used to try and close down an argument by the speaker asserting that what they are saying is true, no matter what the other person thinks.
So it's probably best to take it as a joke name, in a grand tradition that Hergé began in Soviets
, rather than a sophisticated clue to identity.
I must also add that I was fairly sure that there is actually a reference somewhere in the same book, where Justens & Préaux point to Hergé having flirted with using the same punning name for someone else in another book, which would further suggest that it is less likely to be some sort of code, and just Hergé using a gag that he'd had in mind for some time - but sadly I haven't been able to find it again, so I may be mis-remembering. If I do come across it, I will update!