Myriad Construct

• WOTC Official Reminder Textofficial rules
  Kicker — Kicker [cost] (You may pay an additional [cost] as you cast this spell.)

• WWizards of the Coast2020-09-25
  Official Ruling
  An ability that triggers when a permanent becomes the target of a spell resolves before the spell that caused it to trigger. It resolves even if that spell is countered.
• WWizards of the Coast2020-09-25
  Official Ruling
  If a spell targets Myriad Construct more than once, its last ability triggers only once.
• WWizards of the Coast2020-09-25
  Official Ruling
  If you don't sacrifice Myriad Construct as its last ability resolves (perhaps because its ability triggered more than once and you've already sacrificed it), you still create Construct tokens. The number of tokens you create is determined by Myriad Construct's power as it last existed on the battlefield.
• WWizards of the Coast2024-11-08
  Official Ruling
  The kicker ability doesn't let you pay a kicker cost more than once.
• WWizards of the Coast2024-11-08
  Official Ruling
  If you put a permanent with a kicker ability onto the battlefield without casting it, you can't kick it.
• WWizards of the Coast2024-11-08
  Official Ruling
  If a card or token enters as a copy of a permanent, the new permanent isn't kicked, even if the original was.
• WWizards of the Coast2024-11-08
  Official Ruling
  If a spell's kicker cost was paid, the spell is "kicked."
• WWizards of the Coast2024-11-08
  Official Ruling
  To determine a spell's total cost, start with the mana cost (or an alternative cost if another card's effect allows you to pay one instead), add any cost increases (such as kicker), then apply any cost reductions. The spell's mana value remains unchanged, no matter what the total cost to cast it was.
• WWizards of the Coast2024-11-08
  Official Ruling
  If you copy a kicked spell on the stack, the copy is also kicked. If the copied spell is a permanent spell, the token the copy of that spell becomes when it enters is also kicked.

Rulings via Scryfall