Multicolor Matters is already a somewhat supported theme, and it can work well within this archetype
Set Symbols - Your Card's Birth Certificate Set symbols are like timestamps on your cards, telling the story of when and where they entered the Pokemon world
He has a power of 2 and Life of 3 as well as the abilities Lifelink which lets you heal for all damage he deals, and Throw Wide the Gates
Theme Card Thryx, the Sudden Storm Voracious Greatshark Delightful Discovery Brineborn Cutthroat Capture Sphere Naiad of Hidden Coves Opt Pestermite Spectral Sailor Starlit Mantle Stinging Lionfish Undersea Invader Thriving Isle 7 Island 0017_MTGJ25_Theme: Surprise
It has not only an effect that deals damage to them, but also flash, so it can kill a small flock and surprisingly eat the biggest threat your opponent may have
Her search has taken her across the Multiverse, even catching her within the machinations of an interplanar war, all without a hint as to her mentor's location