Mystery's Riddle 2 - Advanced Alien School

[Adventure]

I have to say I am really clueless at level 39 for at least 45 minutes. Besides the pic's name I didn't found any clues in the source. I really don't know what to do with the story. I also can't find where all the flags are from. Actually I didn't found anything out.

Have mercy and please help me.

[Mistery]

Remember the "database with the strange color" mentioned on the main page of the riddle?
You might find there something useful in the

Alphabets and Language

area to decode the small pics

Let me know if you need more help

[Adventure]

Hehe, I totally forgot to look in the database with a strange color. Thanks, Mystery, I found the first egg. Looks like we gonna learn a new dance.

[Mistery]

Yep I'll be around for an hour, so let me know if you still get stuck, because it's a tricky level

[Adventure]

Well,

I found the hidden sentence in the story, but I don't know what to do. I thought I had to change a part of the url, but that is not working.

Shall I PM you what I found?

[Mistery]

You seem to be on the right track, Adventure.
But now also read the second line on the level page carefully.

Change 2 things

If this doesn't help, feel free to PM me

[Adventure]

That was indeed tricky. But I got it. Thank you very much, Mystery. You are a great and helpful teacher.

Working on level 40..

[Mistery]

Well done, Adventure
I'm here if you need help

[Adventure]

Thanks.

I am kinda stuck at level 41.

I have seen the clue in the source and I know what is correct, but I think there is something more that I don't see.

A little tiny hint is very welcome.

[Mistery]

Hmmmm, you just need to figure out what is correct. PM me if you like

[Adventure]

And again I am stuck. This time at class 47.

I found the hidden message in the story and I assume it tells me how to decode the last sentence at the page, but the message is too cryptic for me to understand. I made some google searches but they didn’t brought me further. Just a guess but has it something to do with math or the ADFGVX cipher?

[Mistery]

Have you

looked at the source carefully to see an additional hint?

[Adventure]

I looked in the source, but I didn't see a hint. I am going to look more carefully. Thanks.

Btw, I found out what the message means. Well, I think I did because it is alien related.

[Mistery]

Probably

[Adventure]

I think I have found the hint in the source, but I am not completely certain of it, because it doesn't seem to help me.

I am going to PM you.

Edit: Thank you, Mystery!!