My brain has been taken over by three separate Sonic Underground AU's rn.
First one I've tried a lot, but I think I finally figured out how to get it in a way that I like. It's the Restart AU, and it's going to be almost entirely PMV's. In the AU, the regular game world ended early, due to mobians on the mainland trying to siphon the chaos energy. When Sonic gathered the chaos emeralds to try to keep all the energy from being captured and destroying the planet, they shifted him and everyone on Angel Island to wait in the special zones. A long time and a reincarnation later, Underground Sonic has just broken the stored chaos crystal in his mother's palace as they finally reach peacetime, and realizes that the kingdom is spinning towards the very same situation that destroyed the world the first time. Aleena was a major part of creating the energy siphon, and still fears chaos energy in the new world.
Practically an opposite one, for Aleena at least, this one I call Pocket Moboduen AU (mostly because I haven't come up with another name yet) where Moboduen is part of a pocket dimension, like the Little Planet from Sonic CD, it can phase into the same plane of existence as the rest of Mobius. Underground/game mixture again. Julian Robotnik is Eggman's cousin, and has been ruling Moboduen, he summons Sonic to the pocket dimension so that he can have a puppet king/strengthen his ability to rule. Except that this Sonic spent a long time in Camelot before they found that dimension's king arthur, so he ends up having a lot of fun tricking Julian into handing over control of the kingdom piece by piece. (This Aleena has been traveling since Julian took over, to try to learn and gain enough power to find her missing son and keep her children safe from even fate).
Third one is my most lighthearted one. I legit don't even have a nickname for it and have to come up with one. Sonic underground/game crossover. Sonadow. Shadow is working on restoring the ARK to be a research station and has reclaimed the Robotnik name (he doesn't want Maria's name to be tainted by desperation. and by Eggman) Sonic and Shadow very casually get married on Angel Island by Knuckles, and Tikal decides to send Sonic's family an announcement. She shows up in the middle of court and says "Great blessing will come of the union between the House of Hedgehog and the line of Robotnik." and dips. Leaving the underground family with the vaguest marriage announcement ever that they think is a prophecy that one of them has to marry a Robotnik.
