It really does look like Zuko, but according to DiMartino in the Avatar: The Last Airbender The Art of the Animated Series artbook, Konietzko originally designed Zuko as a scary-looking kid with a scar over one eye to act as a young villain opposite Aang
It enables a ton of synergies, plus the life loss makes it a great win condition in a land sacrifice deck
To add further complexity to the card's placement, Greninja ex isn't exactly a card that receives a great deal of competitive attention
It balances the upper end of the spectrum where super competitive users will be making their wild creations with giving a nice platform to newbies to experiment peacefully without being left with just a starter deck and the shirt on their back
Xyris, the Writhing Storm Xyris, the Writhing Storm has a few notable play patterns
introduced four tribal-themed decks with 100 cards each