Much of the removal in Modern Horizons is slow or clunky, so having a cheap, disruptive threat that synergizes super well with ninjas and blink while being outstanding by itself makes it a top tier common
In a singleton format you have to run a set of cards that all fulfill the same basic function, so instead of running 4 copies of Harmonize, you might run Harmonize, Greater Good, Beast Whisperer, Return of the Wildspeaker, Garruk, Primal Hunter, Shamanic Revelation, Soul's Majesty and Rishkar's Expertise
Sokka, Bold Boomeranger might not be a Bender, but he benefits a lot from instruction, gaining a +1/+1 counter whenever you cast an artifact or Lesson
Tap it for one green mana
Sephiroth, One-Winged Angel Color Indicator: Black Legendary Creature Angel Nightmare Avatar Flying Super Nova As this creature transforms into Sephiroth, One-Winged Angel, you get an emblem with Whenever a creature dies, target opponent loses 1 life and you gain 1 life. Whenever Sephiroth attacks, you may sacrifice any number of other creatures
