If you choose not to put the nonland permanent card you reveal onto the battlefield, you’ll put it on the bottom of your library with the other cards.

Each Storm’s triggered ability can copy the Storm spell even if that spell is countered before that ability resolves.

If your commander was countered, that time you cast it still counts.

Each copy resolves one at a time. Any abilities that trigger on the permanent entering the battlefield resolve before the next copy resolves. The original spell is the last to resolve.

If your library no longer has any nonland permanent cards, you’ll reveal your library and then put it back in a random order.

The copies are created on the stack, so they’re not “cast.” Abilities that trigger when a player casts a spell (such as the Storm’s ability itself) won’t trigger.

Each Storm’s triggered ability counts only how many times you’ve cast your commander from the command zone before that triggered ability resolves. If you cast your commander again later, you won’t get another copy.

If you have multiple commanders, you’ll copy this spell for each time you’ve cast either of them. For example, if you’ve cast one commander once and one twice, you’ll copy this spell three times.