Seishi Ichida (生死一打, Seishi Ichida; literally: Death Stroke) is the main antagonist of the series and the one of most strongest contractor in the universe. Seishi descends from ages before others came into existence.
- Regenerative Healing Factor and Immortality: Seishi possesses a superhuman healing factor that allows him to regenerate damaged or destroyed bodily tissue with far greater speed and efficiency than an ordinary contractors. Seishi is able to heal from injuries such as slashes, puncture wounds, bullet wounds, beheading, and severe burns within moments. His healing factor is significantly more powerful than any contractor as he can regrow missing limbs and organs and was able to recover after one of the contractors liquidated everything from his waist up. His head or any other limb can be reattached using this ability, but has to be placed in the proper place. Even though being beheaded, Seishi can still move his body normally. His healing factor is mentally driven to a partial extent. With his healing factor he can survive in the vacuum of space , survive a nuke blast, and was even said that throwing him in a massive supernova won't kill him. It has been confirmed that he is biologically immortal.
His healing factor provides him with an extended lifespan by slowing the effects of the aging process to an unknown degree. His life span is extended to such a degree, that he survived for over thousand years before finally being turned as a stone statue.
- Immunity And Resistance : The unique regenerative qualities of his healing factor also extend to his immune system, rendering him immune to the effects of all known diseases and infections. His body is highly resistant to most drugs and toxins. For example, it is extremely difficult, though not impossible, for him to become intoxicated . He can, however, be affected by certain drugs, such as tranquilizers, if he is exposed to a large enough dosage. The healing factor causes his brain cells to be in a constant state of flux and regeneration, rendering him immune to psychics .
- Enhanced Mind: Able to utilize 10 times more than a human's brain capacity for information storing and sorting, his mind is practically a computer built for strategy and problem solving. He can work out any sort of battle or attack ahead of time and predict an enemies movements based on what they have displayed so far, showing that his memory borders on almost total recall. He is also ingenious in devising solutions against superior aspects of an opponent, can observe and exploit, and can calculate distance, time, and speed at lightning-fast speeds. His sense of time is also superb, bordering on perfection. The most promising usage of his intellect would be the invention of Toxin.
- Meta-'Human Strength: He possesses the physical strength of an above average meta-human. He is capable of lifting up to 600lbs to 800 lbs at max but no more. He is capable to defeating 10 men on his own. His physical strength has increased slightly after learning karate.
- Hand to Hand Combatant: He is an above average hand to hand combatant capable of going immediate hand to hand combat. His skills were improved after mastering karate, and he has shown the ability to incorporate swordsmanship to his hand to hand combat skills.
- Expert Swordsman: He is a brilliant swordsman, planning his exploits many months even years in advance, he has defeated several swordsman with his skills. He has never been defeated in a swordfight until he met Eric.
- Enhanced Senses: His senses are highly superior as well, making him able to see, hear, smell, feel, and taste things six times better than an ordinary human. He can also almost immediately react to his senses.
- Ability Negation And Contract Absorption: He has the power to nullify the powers of others. He can cancel out the powers of others, making them unable to utilize their powers as long as they are under the his affect. He can cancel out the elemental powers,
as well as melee type abilities. He is able of negate and nullify every concepts, powers, universal definitions, laws and boundaries making him to be immune to everything and anything. He can also induce or give others the ability to be immune to some things. While contract absorption allows him to absorb and achieve other contractors powers with a mere touch of hands. Even with the slightest touch he can steal and strip them of their powers. Till date he has absorbed and achieved the abilities of 100 contractors, giving him full access to their powers. Some of his known achieved powers are:
- Molecular Acceleration
- Density Manipulation
- Gravity Manipulation
- Time Travelling
- Time Stopping
- Portal Creation
- Weather Manipulation
- Telekinesis (micro levels)
- Pressure Manipulation
- Electromagnetism Manipulation
- Multi-Directional Vision
- Darkness Manipulation
- Cloning (However, clones age 10 times faster than normal humans and posses no emotion. Also, they weaken as time passes)
- Fear Inducement
- Force-Field Manipulation
- Bone Manipulation
- Diamond Mimicry
- Elemental Transmutation.
However, other powers of his remain unknown to mankind. One of his primary weakness is he cannot use more than one power at once. But, these achieved powers play an important role in his career as a villain, since, they do not have sort of downside and disadvantages. As, he only receives the contract power of the contractor and not their weakness.
- Obeisance: More than five minutes of continual usage of his original powers causes him to turn into a stone statue. However, he can be restored from strone if bathed in huge amount of energy.
- Toxin: Seishi has been credited with the creation of Toxin, a chemical compound which enhances strength, durability, immunity and speed. Although, he has never used it for himself. Later on Toxin was modified and enhanced by Aboiye, to create a better Toxin which grants him more range of ability.
- Darkest Mage Suit: Darkest Mage suit is the super villain costume doned by Seishi Ichida, it is made from spandex, to ensure he is able to use his agility and flexibility to fullest extent. He can use his full natural and enhanced abilities and slightly acrobatic skills at a relative ease with spandex since spandex is a synthetic fiber known for its exceptional elasticity. It also consists of thick rubber chest plating, arm pads and knee pads, with the maximum amount of rubber with a touch of leather in the chest area. He also dons red nylon wrist bands and normal boots painted red. He also has a dark red cape with black outlining made of polyester. Together all of these make up his suit.