If I were to write another season of Chima, I wouldn't want to bring the stupid flower thing back. That plot device was a rather lame excuse for character motivations. That said, I would want to make Laval a main villain and Cragger the primary protagonist. However, the position of primary antagonist belongs to none other than Scorm... Let me explain;
Since his defeat in the scorpion cave, Scorm has been bitterly pondering what Laval told him at the end of "This may sting a bit." Eventually, Scorm comes to the conclusion that the only way he can justify his own actions is to prove that anyone else in his position would do so too. So, he takes to kidnapping Laval and tortures him with poison or something along those lines until he's finally able to break the lion's spirit. I suppose he could also use Laval's mother, somehow.
Eventually, he manages to convince Laval that the only way to earn power is to crush those who are unable to keep it for themselves. Of course, Laval should eventually turn this philosophy on Scorm's head, resulting in a three-way battle.(Chima, vs. Laval's rebels vs. Scorm's Outlanders)
Following these developments, Crooler and Worriz side with Laval in order to seize their own shares in his wealth whereas the other tribes(led by their respective kings) fight against him. It takes a certain amount of deep thought for Cragger to find his place in the war, but he ends up remembering his own darkest days and chooses to fight Laval in order to maybe get his friend back the same way Laval did to him.
For the bulk of the season there should be various subplots and a multitude of battles between the three factions, eventually ending with the rebels and outlanders rejoining in a common purpose to take all of Chima.
I would make the season end with a twist in which the Hunters return to civilization and turn the tides in the war. At some point earlier on I imagine there would be some mention that they left to go and rebuild themselves away from the already formed chiman society. Sir Fangar himself would have all the brilliance and cunning as before, but less of the psychopathy, and thus would recognize his former traits in Laval. I think it would be neat to end off the season with Laval in recovery and Cragger, Crominus, Lavertus, Lagravis, and Sir Fangar having a discussion about how anyone can be twisted, but they can also change for the better.