It pulls troops towards the center of the spell, making them more vulnerable to splash damage.
The card image shows a tornado with a pig (possibly the Hog Rider's) being sucked into the tornado.
A Tornado damages an enemy unit every 0.5 seconds.
The Tornado can be a replacement for Arrows but it is much harder to obtain and level up due to its rarity and being unlocked at a higher Arena Builder's Workshop (Arena 6).
The Tornado does not affect buildings with its pull effect, nor does it damage them, meaning it cannot be used to finish off low health Crown Towers or activating the King's Tower.
Cast the Tornado near a large group of units, such as a Skeleton Army. The Tornado will take in the units towards the centre of the spell, dealing damage to them and potentially killing them. For reference, a Tornado can almost kill an equivalent level Goblins.
Any unit who is moving opposite to where the Tornado is pulling them will resist the pull, and the unit will not be pulled as far. Because of this, the Tornado works more efficiently the slower the target troop is. For example, a Hog Rider can resist more than a Musketeer because of the amount of speed they have. However, you should also take into account that stationary troops are heavily influenced.
Any unit caught in the Tornado can attack as long as a target is in range. Because of this, ranged troops hardly suffer at all when being dragged away from their target, so it is better to pull them in closer to nullify their range advantage.
The Tornado can be useful at separating units and splitting up and weakening assaults. However, if placed incorrectly, it can be very punishing, as it can drag dangerous enemy troops, such as the Mini P.E.K.K.A., closer to the Crown Tower.
It is difficult to master the Tornado, and a misplacement of this card can result in devastating damage to your Crown Towers. To reduce the chance of this, use dragging instead of tapping when deploying the Tornado as the exact area of effect will be visible.
The Tornado can be used to sweep defending units out of the way. This is particularly effective when trying to preserve glass-cannons to maximise damage output. Tornado is also great with Graveyard, as it can drag defending units like the popular Valkyrie out of the way. In a similar manner, ranged troops can be pulled towards highly damaging units to nullify their range advantage.
It can also be used to drag ranged troops to your high damage dealers. This is an excellent way to play a P.E.K.K.A. Tornado deck. Executioner and Wizard also pair well in the P.E.K.K.A. Tornado deck as their splashing capabilities can be used effectively with the Tornado wiping out hordes of low to medium health units. Using similar thinking, the Tornado can also pull troops to a bomb dropped by your Giant Skeleton or Balloon to kill or, at least, heavily damage them.
Splash troops used in conjunction with the Tornado is devastating as enemy units are clumped together in the centre of the Tornado, leaving them vulnerable to splash damage. A deadly combo is Tornado + Sparky. The Tornado can clump up enemy troops to allow Sparky to kill all of them with her nuclear blast.
You can use this spell to pull troops to the King's Tower to activate it early. This will allow for extra defence, as the King Tower is able to attack any troops that are near the Princess Towers. It is advised to pull high damage dealers to the centre of your side so both Princess Towers can engage it. This prevents the possibility that the unit may deal heavy damage to your Princess Tower. However, cheap troops like skeletons should be placed to maximise the time in the kill zone.
For example, Balloons can be easily destroyed using this strategy thanks to their moderate health and slow movement speed.
It is not recommended to pull extremely powerful troops to the King's Tower such as the Golem or P.E.K.K.A.. Extremely high-health troops will be able to survive the attacks of the three Crown Towers for very long, allowing other troops to do significant damage to the Princess Towers if unopposed. Additionally an extremely powerful troop can also do significant damage to the King's Tower, opening up the possibility that your opponent destroys your King's Tower directly.
The Tornado was added to the game on 11/11/16.
On 15/12/16, a Balance Update increased its radius by 10% and also increased its pulling power. This update also changed its description. It used to say: "Drags enemy troops to the center of the Tornado while dealing damage over time. Doesn't affect buildings."