Under Yugo's hat is...(The following are all Jossed; in episode 26 of season 2 it shows that there are wings under his hat.)
Nox was actually the Unwitting Pawn for the Eliacube all alongThe Eliacube really is sentient and telepathic. And not very nice. All it cares about is being reunited with the Eliatrope and thus seeks to get its attention. As a result, all the business with turning a simple watchmaker into an Omnicidal Maniac was nothing more than an elaborate Batman-Gambit in order to attract the attention of The Eliatrope. It was perfectly capable of traveling back 200 years in time with all that Wakfu, but 20 minutes was all it needed in order to achieve its own objective. The only reason it bothered traveling back in time at all was because Nox had got a little out of hand and was going to kill Yugo unless the wind was taken out of his sails.
In season 2, there will be a love triangle between...Evangelyne, Sadlygrove and Remington and Sadlygrove will win. We know from S.2.E.2. that Sadlygrove has survived so why not?
Qilby is lying about being King of the EliatropesEvidence: Qilby is terrified of Yugo and screams "No! You!? Is that really you?" when he first sees him and faints at the sight of him. And Baby Grougaloragran breathes fire in his face when he meets him. Why is that? And isn't it strange that Yugo is only an adventurer in Qilby's flashback while Qilby gets to be the important wise leader? To top it all off Yugo and Adamai sealed Qilby away in a dimensional space "against his will" during Qilby's flashback and he was only released because Yugo and Adamai used the Eliacube. The truth is probably that Yugo was the king and Qilby was a traitor to the king he wanted to be king, but wasn't chosen. He's probably lying to make himself feel better.
Extending the previous theory, Qilby will be Big Bad of Season 2.Simple process of eliminating unlikely candidtates points us to him. Rushu is a Card-Carrying Villain who was partially Played for Laughs in his sole appearance so far, there is no way he can be a successor to a complex and tragic character like Nox. That he plays a major role in the opening is intentional obfuscation on the part of authors. And should only disqualify him, once we remember, that Nox wasn't in Season 1 opening, while some very minor antagonists were. Remington Smisse, even if he has Hidden Depths, is far too incompetent. He's more likely to be the true foe, than Rushu, but not by much. Importantly, both of them aren't connected to Eliatropes, the quest for whom is going to drive even more plot in Season 2, in any way. And there are no other candidates for a big villain so far. Now, besides the fact that Quilby's behavior is somewhat suspicious, there is circumstantial evidence that points at him. Did someone truly not expect something bad to happen when Adamai guilt-tripped and bullied Yugo into using the Eliacube without saying anything to anyone? That's because the whole process was deliberately framed in a way, generally used to leave the impression of characters' actions being stupid. Seriously, a decision taken because one of the characters was throwing a childish temper tantrum, and another was too soft to say "No" is what usually considered a perfect setup for disaster in fiction. So there is a reason to suspect that the consequences of this decision won't be as beneficial as they seem. Then there is failure of Yugo to extract any sort of useful information from the Eliacube (note, though, that his visions showed a menacing-looking humanoid and attacking dragons, no sign of alien invaders), which left Quilby's words deliberately unconfirmed by any other source. And Quilby's musical theme is just a bit too ominous for a good guy as well. But most importantly, he's the only man so far who might easily fulfill the criteria of being a complex villain with some connection to the Eliatropes. Due to Yugo, again, failing to learn anything from the Eliacube, he holds all the cards and can easily manipulate the Brotherhood into advancing whatever his plan is, and it is very possible that the Eliacube will be left to him for safekeeping as well, giving him the necessary edge in sheer power. So, he is in a perfect position to become the true Big Bad.
The Eliatrope children that were sealed away are the same ones in Les Gardiens.If this is the case, then when Yugo opens the zaap to free them he will find a debris field. And a couple survivors if he's lucky. Since Ankama requires the tears of children to keep its business running...
Mechasms Shall ReturnIf they still exist, or if they even existed to begin with, the Mechasms will make a major appearance as a potential Big Bad candidate, a three-to-four-parter villain, or as a recurring antagonist.
The Eliatrope Children weren't sealed away at all the mechasm wereBecause Rule of Drama demands it. Related to the Qilby theories above. When Yugo opens the zaap to free the children the Mechasm (or maybe just Orgonax) will be released to rain hell upon the world again instead. If this is true though it could result in a Bad Ending for the world of Wakfu
Adamai (and by extension, all dragons) can manipulate Stasis as easily as WafkuAdamai's energy-empowered martial arts glow more purple than blue during his fight with Igole. Plus, Stasis seems to be anti-wakfu, so is probably a more efficient source of power than Wakfu when you are going for purely destructive ends.
The Eliacube has been corrupted in some way by the MechasmNox used the Eliacube as the basis for all his magitek. Yet, for some reason, everything he builds far more closely resembles Mechasm devices than Eliatrope ones.
The Mechasms are the ShushusAssuming that the Mechasms are actually real, they share a great deal in common with the Shushus. Both have an unsatable lust for destruction and the Mechasms could easily have been weakened or propagated into or otherwise become the Shushus.