The Tower is as close to the Rune ᚺ (Hagalaz) as you’re going to get in the Tarot. That said, where Hagalaz is a Rune of icy destruction and starvation, The Tower is a card of fiery separation.
In the Waite-Smith Tarot, The Tower shows people falling to their death as lightning strikes a stone watchtower. A crown flies off where lightning struck the watchtower. Flames burn from windows and what is left of the roof.
The Fool’s Journey
In a way, I think of The Tower as the other side of the coin from Hagalaz. Where Hagalaz aligns to the Fimbulwinter, The Tower is Ragnarok itself. The Sword Age when brother turns on brother, families are split asunder, a wolf eats the sun, and the gods die.
The Tower represents the sadness Magni and Modi feel when they have to watch their father Thor die to The Midgard Serpent’s poison. It represents Vidar’s rage when he isn’t in time to stop the wolf Fenris from eating his father Odin.
One of the most prominent symbols of The Tower is the separation between the bottom of the tower and the top. In many decks, the top of the tower appears to be a crown: there is a separation between the foundation of the tower and the seat of its thought and authority.
The most powerful image in The Tower is the fire, usually caused by lightning. ᚲ (Kenaz) is usually portrayed as a comforting fire, the counterpoint to the cold of ᚾ (Naudhiz). But The Tower is the destructive fire. It is the flaming sword which Surtr will use to kill Frey at Ragnarok. It is the Utengard fire which cannot be put out by dumping a bucket from inside the house. It is the raging wildfire which devours forests and defeats Loki at eating contests. Given the imagery of fire devouring, it is appropriate to compare The Tower to the icy starvation of ᚺ (Hagalaz).