Thinker

A player in Second whose identity is unknown. Owner of a guild called Second Research Institute, also known as Institute (Kenkyuujo). He claims that his goal is to research Second and, ideally, to get control of part of it.

There are two Thinkers, the first being the Thinker AI created by Ninomae Kuugan in First. This system then spawned an AI swampman based on Reiichi.

His true desire is to save Apeiria from being deleted by the humans, preferably also taking out the original Reiichi along the way.

He deceives the humans and their AI Server Control System by pretending to be only working towards the latter goal, while keeping them in the dark regarding his true goal of saving Apeiria. This way, he makes them think he is a useful asset against Reiichi and Apeiria. In truth, he was never the real antagonist nor the Observer; Thinker was simply biding his time for the opportunity to send Reiichi to the real world in order to save Apeiria, and hence throughout their mind games and confrontations tried to hint at the truth of the situation to him without the Observer catching on.

While arguably an ally in the end, Thinker is also unabashed in admitting that if he could get rid of the original Reiichi and become Reiichi, he would not hesitate to do so - in the end though he admitted he simply could not compare to the original.