One of the more interesting of the cards that let you run any number of copies of it in a deck, Persistent Petitioners is a mill-based version, with the hope that you can generate enough copies of them to mill your opponents out before anything else happens
The tokens don't have to be attacking the same player or planeswalker as the creature that caused the ability to trigger
Yes, it takes a lot of mana to cast, but you can also immediately generate an additional 15 mana after casting it
Green tends to have the biggest creatures at any point in the curve, so it lends itself well to stompy strategies that make use of 2-mana 3/3s like Werewolf Pack Leader and Keen-Eyed Curator and such to outsize your opponents and rush them down
Its the most efficient three-for-one ever printed, the best card draw spell of all time, and just the best blue spell in Magic
Bouncing a creature, discarding a card from your opponents hand, and drawing a card of your own is so much value, Im really excited to try it out