Information Exchange Ability

This information exchange ability is the ability of Sigma.

Description
Upon contact with another person, the ability allows Sigma to exchange the information he wishes to know most with the information the other person wishes to know most.

As a side effect, the person that Sigma exchanges information with may experience momentary loss of consciousness as a result of a possible information influx. For example, Atsushi Nakajima once collapsed after Sigma apparently used his ability on him to transfer information about the page's location being held by the Decay of the Angel. Ango Sakaguchi conjectured that his brain might have temporarily surrendered consciousness to sort the large amount of information, a similar experience that his own ability also caused before.

Apparently Sigma's ability also allows him to extract information from corpses, but if he hasn't been dead for very long. During his conversation with Dazai, Dazai would reveal that the first reason he chose him was so that Sigma could "read" the future plans of Fyodor's supposed drowned body.