Cards similar to Morph include Zoetic Cavern
To be fair you could start immediately with one of these but, honestly, progressing from a basic deck to a planeswalker is an easier learning curve
Of all of these, Iroh, Grand Lotus seems to be the most likely play Sokka thanks to him being able to turn on all the graveyard synergies for Lessons
Between the artifact heavy The Brothers War and the enchantment-loaded Kamigawa: Neon Dynasty, there will rarely be a time when it doesnt have a target
Card Text: Whenever a player draws their second card each turn, that player exiles the top card of their library
Its nothing fancy, but playing this on turn one allows you to play a four-cost card on turn two - and its rare that such a speedy start to a game doesnt result in a massive advantage