You can activate one ability of a planeswalker you control once a turn, but only during a main phase when you would cast a sorcery
Song of the Dryads will enchant any opposing permanent and turn it into a Forest, so from Academy Ruins to Gaea's Cradle and from Commanders so they won't die and get recast, Elspeth's, Sun's Champion or Consecrated Sphinx, nothing can answer
And that's before we get to the fact that it's almost impossible for blue decks to deal with the card
Having its ETB trigger twice (if not more) can grant you a significant advantage if you play it right
You have an advantage in combat: There arent a lot of combat tricks in Scars, but when youre running infect, you know that most wont blow you out too bad
Astrologians Planisphere in Standard If Astrologians Planisphere sees any Standard play, it will be in Izzet Prowess