Theme-wise. Note, that while "normal" Titans are grotesque, they look like modern-day Earth humans
Overweight, no purpose, mindless consumers. The survivors die in droves, other than the heroes (and a lot of them too) breakdown in the face of the horror, and go mad or turn on each other.
A recurring theme in Attack on Titan
is the need to never give up and keep fighting in the face of adversity. If you don't fight, you can't win. Most characters have something that is currently out of their reach:
Eren and Armin want to be free from the walls, but can't because of the Titans. Mikasa wants a peaceful life, but can't be happy unless Eren is safe. Levi and Erwin want a better tomorrow for humanity, but conspiracy factions are holding humanity back. Annie, Reiner and Bertolt want to return home to their village, but can't until they complete their mission. In the past, Hange wanted to learn more about the Titans, but the military refused to support Titan research. Historia wants to live for herself, but other people keep controlling her destiny.
Each character has something they want, but they can never reach their goals if they sit down and do nothing. Humanity as a whole represents complacency. After 100 years, they are no closer to defeating the Titans because the powers within the walls no longer have any interest in doing so. The common people have largely dismissed the existence of Titans prior to Wall Maria's breaching. Humanity cannot win against the Titans because they no longer wish to fight.
The main characters fight, and struggle, and some are even willing to offer their lives while pursuing change. Though the odds seem hopeless, nothing will ever happen unless you are willing to risk sacrificing something.
- 0/XXII The Fool: A naοve soul with untapped potential. Freedom and adventure. Infinite possibilities. - Eren
- I The Magician: A focused, capable man. Desire for action, initiative, resourcefulness, manipulation. - Hanji
- II The High Priestess: A veiled woman with a closed book. Mysterious, wise, secretive. - Annie
- III The Empress: A fair, powerful woman. Nurturing, femininity, prosperity, motherhood. - Petra
- IV The Emperor: A crowned, powerful man. Leadership, action, decisiveness, stability. - Erwin
- V The Hierophant: A great priest. Religion, obedience, conformity, faith. - Pastor Nick
- VI The Lovers: A young couple, tempted by love. Romance, relations, determining personal values. - Krista
- VII The Chariot: A king's magnificent chariot pulled by two horses. War, victory, self-control. - Mikasa & Levi
- VIII Strength: A gentle maiden tames a fearsome lion. Compassion, virtue, courage. Inner strength. - Armin*
- IX The Hermit: An old man illuminating the darkness. Solitude, need for independence, introspection, wisdom. - Ymir
- X The Wheel of Fortune: A wheel with several outcomes on it. Unpredictability of life. Luck, misfortune and perseverance. - Connie
- XI Justice: A blind woman with a sword and scale. Fairness, objectivity, truth, rationality. - Jean
- XII The Hanged Man: A man hung upside-down in thought. Restriction, need for deliberation, letting go, self-sacrifice. - Historia
- XIII Death: The Grim Reaper. An end, and a new beginning. Change. New directions. - Marco
- XIV Temperance: An angel pouring water between vases. Patience, slow and steady, purposeful. - Pixis
- XV The Devil: A demon with chained men. Hedonism, bondage, addiction. - The Military Police
- XVI The Tower: A massive tower is toppled by lightning. Disaster, sudden change, bad omen. - The Beast Titan
- XVII The Star: A woman nourishes the land with water beneath a starry sky. Hope, altruism, renewal. - The Survey Corps
- XVIII The Moon: A dog and a wolf howl to the moon. Deception, anxiety, insecurity. - Reiner & Bertolt
- XIX The Sun: Children frolic under the sun. Fun, exuberance, positive. - Sasha
- XX Judgment: An angel awakens the dead to be judged. Conclusion, moment of truth, absolution. - ???
- XXI The World: A figure dances in celebration. Fulfillment, harmony, closure. - ???