14 Flotsam - Riffraff #72/204 & Jetsam - Riffraff #76/204 Emerald Ink Dreamborns Flotsam and Jetsam are no strangers to the Disney Lorcana world, also having Amethyst Ink cards that appeared in The First Chapter set
Reigning Victor is fine, but not really worth three colors of mana
In other words, what Kiora would bring to the table under a hybrid color identity rule change wouldn't be anything you can't do with two different cards right now, but rather just a good option that can do both at once, in either green or blue decks
Cards like Aether Adept can remove blockers so you can get aggressive, or you can use them defensively to thin out any opposing frontlines
Unfortunately, the decks archetype doesnt look like it will make a good starting point for truly competitive play
Its also just a good card to have around if youre making tokens or bringing things back to life