Zornsturm-Scharbildung

Each of the tokens must attack the appropriate player if able, not a planeswalker that player controls or a battle they protect.

If one of the Elemental tokens is tapped or is affected by a spell or ability that says it can't attack, then it doesn't attack.

If one of the tokens can't attack the appropriate player, its controller is free to have it attack any other player, planeswalker, or battle or to not attack with it. If there's a cost associated with attacking the appropriate player, its controller is free to have it attack any other player, planeswalker, or battle or not attack with it. However, if there's a cost associated with that token attacking at all, that token has to attack the appropriate player or not attack.

To determine the total cost of a spell, start with the mana cost or alternative cost you're paying, add any cost increases, then apply any cost reductions (such as that of Furygale Flocking's first ability). The mana value of the spell is determined by only its mana cost, no matter what the total cost to cast that spell was.