Returning two Islands and getting to draw two cards for free can be very strong, especially for decks like Storm or Doomsday that are trying to win the same turn
Sephiroth has a number of cards between this set, the commander decks, and the starter decks, but I think this one is undoubtedly the most powerful
And dont even get us started on Unwinding Clock
Theres the option to throw in some flavorful self-mill sagas like Tymaret Calls the Dead, The Binding of the Titans or Death in Heaven and then scoop your gods out with type-sensitive mass reanimation from Patriarchs Bidding, Haunting Voyage, Replenish, Resurgent Belief or Primevals Glorious Rebirth
Strange Loops Sometimes, a game of Magic gets very repetitive
Winged Hive Tyrant is another way to help out your team, providing haste and flying to all of your creatures with counters on them