The Tower is one of the most violent cards in Tarot. It shows unexpected changes or sudden realizations that in most cases, we are not prepared to face. That said, the Tower can also be the most cathartic card. It removes illusions and opens up new doors. The Knight of Swords is logical, witty, analytical, just, but he can also be impatient, judgmental, ruthless and verbally aggressive. The combination of the Tower and the Knight of Swords points to unexpected and disruptive news/developments.
To understand the elemental relationships between the cards, we should always take into account their actual meaning. The elements of these cards are Fire (Tower) and Air (Knight of Swords). Undoubtedly, this is a very powerful combination, as from an elemental point of view, the two cards strengthen each other becoming an unstoppable force. It's very difficult to stand in the way of such a force without taking serious damage, which means that if this combination appears, it's best that we go with the flow of things rather than resisting or trying to bring about changes that are beyond our control.