Seth Turner Sato

Seth Turner Sato is the third character introduced in The Human Game. He used to be one of the players before he fell into despair and became nullified.

Personality
Seth considers himself one of the most awesome people to have ever existed, and believes everyone is in awe of this. But while he may look handsome, his personality is the complete opposite. He is incredibly selfish and narcissistic, and cares little about anyone's needs except his own, believes everyone is here to serve him, and feels offended when someone refuses to do what he says. As a result, it's not long before no one wants anything to do with him, but he seems ignorant of how obnoxious he is to others. His vanity is kind of a theme - even his nullification has glitches saying things like 'I will become like God'.

After he becomes nullified, his personality changes dramatically - he becomes cold, calculating and demanding. He claims to have become something above human. As such he doesn't have any problems fighting his old friends, killing innocent people, or forcing people to do things against their will. He started to ignore feelings and disregards anything that goes against his ideals.

Role in the story
Seth plays a pivotal role in the story. He is the third character to be introduced, annoying Kate and Joe by doing so. At the first meeting, he is paired up with Thalia and Connor to seek out the other two who did not appear at the first meeting. It turns out one of them is Abigail and the normally so stoic and egoistic Seth also thinks her appearance in such a situation is insane. He does not want the others to lie to her about the situation because she is young, but after her insistence, he explains it to her honestly. However, when it is revealed that she is a spirit medium, he starts mocking her.

After the second meeting commences, he takes Daniel to Camilla's room, interrogates and threatens him with a knife under the suspicion of having stolen something unspecified from him. However, he walks away after he feels something calling him. Daniel tries to follow him, but quickly runs back after he sees Seth is being nullified.

He spends the rest of the story in his nullified form, chasing the others into a room. When he tries to get out of the library, a being called a major distracts him. They have a conversation until they leave.

Trivia

 * There were multiple reasons why he was the first to nullify.
 * He is the 'guinea pig'. Someone had to go first.
 * Friday didn't want to have a 'nice' character to go first. So she deliberately made him unlikable in the hopes of becoming a 'scrappy' in the fandom.
 * Seth has a definite butterfly motif. It's not only present in his Null form and his symbol, but his shades give him a slightly insect-like look and he wore bright colors before being nullified.

Butterfly symbolism
Butterflies have many symbolic meanings in different cultures and lore.
 * Butterflies are generally associated with transformation.
 * Butterflies can also represent death and rebirth.
 * In Japanese lore, butterflies are the personifications of souls. Note that Seth is at least partially Japanese.
 * The ancient Greek word for butterfly means "soul" or "mind".
 * Two butterflies flying together represents love.
 * People in Devonshire would traditionally rush to kill the first butterfly they see in a year, or else face a year of bad luck.
 * In the Philippines, a lingering black butterfly or moth in the house is taken to mean that someone in the family has died or will soon die.
 * Seth's butterfly motif might refer to the phenomenon known as the "butterfly effect", referring to how a small change in time leads to large consequences; Seth in fact invokes the butterfly effect, like Cancel says at one point.