Spinerock Tyrant

• WWizards of the Coast2025-11-17
  Official Ruling
  Any damage dealt to creatures by a source with wither, whether it's combat damage or noncombat damage, is dealt in the form of -1/-1 counters.
• WWizards of the Coast2025-11-17
  Official Ruling
  If the spell that's copied is modal (that is, it says "Choose one —" or the like), the copy will have the same mode or modes. You can't choose different ones.
• WWizards of the Coast2025-11-17
  Official Ruling
  If the spell that's copied has an X whose value was determined as it was cast, the copy will have the same value of X.
• WWizards of the Coast2025-11-17
  Official Ruling
  You can't choose to pay any additional costs for the copy. However, effects based on any additional costs that were paid for the original spell are copied as though those same costs were paid for the copy too.
• WWizards of the Coast2025-11-17
  Official Ruling
  The copy will have the same target unless you choose new ones. If you change the target, the new target must be legal.
• WWizards of the Coast2025-11-17
  Official Ruling
  The copy is created on the stack, so it's not "cast." Abilities that trigger when a player casts a spell (such as conspire's triggered ability that creates a copy of the spell) won't trigger.

Rulings via Scryfall