Empty the Warrens

• WOTC Official Reminder Textofficial rules
  Storm — When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.

• WWizards of the Coast2022-12-08
  Official Ruling
  Spells cast from zones other than a player's hand and spells that were countered are counted by the storm ability.
• WWizards of the Coast2022-12-08
  Official Ruling
  The copies are put directly onto the stack. They aren't cast and won't be counted by other spells with storm cast later in the turn.
• WWizards of the Coast2022-12-08
  Official Ruling
  A copy of a spell can be countered like any other spell, but it must be countered individually. Countering a spell with storm won't affect the copies.
• WWizards of the Coast2022-12-08
  Official Ruling
  The triggered ability that creates the copies can itself be countered by anything that can counter a triggered ability. If it is countered, no copies will be put onto the stack.

Rulings via Scryfall

• WO
  Wizards of the Coast2013-02-01 · edited

  Empty the Warrens was banned in pauper on February 1, 2013. Beyond permission spells, the Pauper format has a limited number of answers to storm spells such as Empty the Warrens and Grapeshot. Statistically speaking, they are not sufficient to support a diverse competitive metagame. Source: https://magic.wizards.com/en/news/latest-developments/rapid-hybrid-ization-2013-02-01
• WO
  Wizards of the Coast2013-01-28

  Empty the Warrens was banned in pauper on January 28, 2013. No public reasoning provided. Source: https://magic.wizards.com/en/news/january-28-2013-dci-banned-restricted-list-announcement-2013-01-28