I believe the restriction of only getting to use instants or sorceries of 3 mana value or less is a good restriction and plays on the youth in which Aang flees
The best part of them though, is that your Creature spells cost one generic mana less to cast for each point of life your opponents have lost this turn
If you can afford the colorless, this card is an absolutely reasonable option for an aggressive red deck
Ravensburger has shed light on what to expect from its ninth Disney Lorcana set, Fabled
Yasharn, Implacable Earth Yasharn, Implacable Earth is particularly good these days when Wizards of the Coast (WotC) has unleashed the Treasure floodgates and nearly every deck has some busted card that makes a bunch of Treasures
Niv-Mizzet, the Firemind Back in the beginning, if you took 21 damage from a general, you lost, regardless of where that damage came from (despite the fact that the idea came from three hits from one of the original Elder Dragons)