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
This can be very useful if you have cards like Spirited Companion or Ravenous Chupacabra, so you'll have guaranteed value every turn
The CGC Pristine 10 is the ultimate achievement, assigned only to cards that are flawless even under 10x magnification across all four grading criteria: centering, corners, edges, and surface
In a nutshell, if you are new to MTGA, claim as many Arena codes as you can so you can open packs, build them into your decks to complete the daily quests , then go for Jump In
I feel Wizards of the Coast regularly highlights that having ways to remove lands can matter, but it seems a large portion of the player base doesnt utilize this tool often enough
Located on the bottom right of an MTG Arena card is a heart