I think an epic twist villain for Dragons Rising can be Fritz aka the Formling Finder. Kinda (Definitely) Parallel to Harumi, hating a Ninja for ruining their life + also being close with a Ninja.
Fritz is obviously close to Cole (that is like, one of his two dads). But, Fritz is also a Formling. Formlings age differently from other species so that means Fritz was probably a kid for long enough to be alive & have an awake mind during the reign of the Ice Emperor.
We cnaonly don't know how Fritz & Spitz had gotten lost/forgotten to be in the Land of the Lost. Spitz is total mystery. But, it is easier to assume with Fritz as he is a formling.
Maybe Fritz tried to escape yet failed and fell somewhere frozen for decades until the reign ended. A recently unfrozen Fritz wakes up in a whole other place. One for the forgotten and lost..
The Ice Emperor did this.
If the Ice Emperor never had his rule, he would of never been forgotten.
If he finds out Zane = Ice Emperor, it would be so SHSJSKKSKSSKKS. The tyrant that froze you and your people (that had even forgotten you) is a supposed hero on the same team with your father-figure?! The Never-Realm inhabitants may not know this but, Fritz might due to his connections with Cole.
Deceptive via acting nice/normal to Zane while plotting personal revenge can be interesting for Fritz.
Villain/Antagonistic Small Kids, we need more of those after Kid Lloyd went bye
Temporary or not, it seems cool + more consequences on Ice Emperor stuff so yeah.