If you run Grave Pact or Dictate of Erebos, every time you sacrifice one of your creatures, each opponent must sacrifice one too
It starts off fantastic with no other work needed (compare the something like Resolute Reinforcements), but Ajani, Nacatl Avenger is just absurd if it flips early enough in a game
When Sparkling Crystal is attached to a Tera mon, the Attacks of that Pokemon are reduced by 1 of any Energy type
It may be somewhat overcosted at 6G, but in a deck focusing on green mana, this Sorcery can utterly flood the board with Wolves that will overrun your opponents with ease
But often it is for mutual benefit or the benefit of a single player, not a big deal on its own, except when two friends use Trade Secrets to draw their whole decks and go into a war to combo off while the rest of the table is blown away
The first is through Discord