Avatar: The Last Airbender Promos

Clue

Enchantment

When this enchantment enters and at the beginning of your upkeep, you lose 1 life and create a Clue token. (It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you attack, put X +1/+1 counters on target attacking creature, where X is the number of permanents you've sacrificed this turn. If X is three or more, that creature gains lifelink until end of turn.

Obsessive Pursuit

Avatar: The Last Airbender Eternal

Sorcery — Lesson

Earthbend 3, then earthbend 3. You gain 3 life. (To earthbend 3, target land you control becomes a 0/0 creature with haste that's still a land. Put three +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)

Cracked Earth Technique

Creatures you control have "Whenever this creature becomes tapped for the first time during each of your turns, put a +1/+1 counter on it."

Tale of Katara and Toph

Kamigawa: Neon Dynasty

Legendary Creature — Human Samurai

First strike
Whenever a Samurai or Warrior you control attacks alone, untap it. If it's the first combat phase of the turn, there is an additional combat phase after this phase.