Thunderclap Drake

If you have multiple commanders, you'll copy the next instant or sorcery spell you cast this turn for each time you've cast either of them. For example, if you've cast one commander once and one twice, you'll copy that spell three times.

The last sentence of Thunderclap Drake's rules text was inadvertently omitted from the card. Its Oracle text has been updated to include that sentence.

If a spell that's copied has an X whose value was determined as it was cast, the copies will have the same value of X.

Thunderclap Drake's second ability doesn't change the mana cost or mana value of any spell. It changes only the total cost you pay to cast instant and sorcery spells.

If the spell that's copied divides damage or distributes counters among a number of targets, the division and number of targets can't be changed.