Thousand-Year Storm

Spells you've cast that were countered were still cast, and so will add copies when Thousand-Year Storm's ability resolves for later spells in the turn.

The copies will have the same targets as the spell they're copying unless you choose new ones. You may change any number of the targets, including all of them or none of them. The new targets must be legal.

You can't choose to pay any additional costs for the copies. 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.

If an effect instructs you to cast multiple spells, they're cast one at a time in any order.

Thousand-Year Storm's ability will copy any instant or sorcery spell, not just one with targets.

If the spell has damage divided as it was cast, the division can't be changed (although the targets receiving that damage still can). The same is true of spells that distribute counters.