Parasitic Impetus

• WWizards of the Coast2020-04-17
  Official Ruling
  Parasitic Impetus causes you to gain life, not the attacking creature's controller.
• WWizards of the Coast2020-04-17
  Official Ruling
  If you are the attacking creature's controller, you lose 2 life and gain 2 life. You won't lose the game if your life total is 0 in between these two events.
• WWizards of the Coast2023-06-30
  Official Ruling
  Attacking with a goaded creature doesn't cause it to stop being goaded. If there is an additional combat phase that turn, or if another player gains control of it before it stops being goaded, it must attack again if able.
• WWizards of the Coast2023-06-30
  Official Ruling
  If a creature you control has been goaded by multiple opponents, it must attack one of your opponents that hasn't goaded it, as that fulfills the maximum number of goad requirements. If a creature you control has been goaded by each of your opponents, the creature must attack an opponent (rather than a planeswalker or battle), but you choose which opponent it attacks.
• WWizards of the Coast2023-06-30
  Official Ruling
  If the creature doesn't meet any of the above exceptions and can attack, it must attack a player other than the controller of the spell or ability that goaded it if able. If the creature can't attack any of those players but could otherwise attack, it must attack a planeswalker an opponent controls, a battle an opponent controls, or a player who goaded it.
• WWizards of the Coast2023-06-30
  Official Ruling
  Being goaded isn't an ability the creature has. Once it's been goaded, it must attack as detailed above even if it loses all abilities.
• WWizards of the Coast2023-06-30
  Official Ruling
  If, during a player's declare attackers step, a creature that player controls that's been goaded is tapped, is affected by a spell or ability that says it can't attack, or hasn't been under that player's control continuously since the turn began (and doesn't have haste), then it doesn't attack. If there's a cost associated with having a creature attack a player, its controller isn't forced to pay that cost, so it doesn't have to attack that player.

Rulings via Scryfall