Baral, Chief of Compliance

• WWizards of the Coast2021-03-19
  Official Ruling
  The cost reduction applies only to generic mana in the cost of instant and sorcery spells you cast.
• WWizards of the Coast2021-03-19
  Official Ruling
  A spell or ability counters a spell only if it specifically contains the word "counter" in its text. If a spell or ability you control causes all the targets of a spell to become illegal, that spell doesn't resolve but it's not countered.
• WWizards of the Coast2021-03-19
  Official Ruling
  To determine the total cost of a spell, start with the mana cost or alternative cost you're paying (such as a flashback cost), add any cost increases (such as kicker costs), then apply any cost reductions (such as that of Baral's first ability). The mana value of the spell is determined by only its mana cost, no matter what the total cost to cast that spell was.

Rulings via Scryfall

• WO
  Wizards of the Coast2018-05-10

  Baral, Chief of Compliance was banned in brawl on May 10, 2018. Baral, Chief of Compliance is both the most popular and most winning Brawl commander in Magic Online one-on-one play, constituting more than 35% of the metagame and achieving a nearly 65% win rate. The counterspell-heavy play pattern Baral encourages also detracts from what players enjoy about the format, effectively nullifying many deck-building choices at too efficient of a rate. Source: https://magic.wizards.com/en/news/news/future-brawl-2018-05-10