Vexen, the Chilly Academic (いてつく学究 Itetsuku Gakkyū?, lit. Freezing Scholar), is the Nobody of Even, Rank IV of Organization XIII, and a reserve member of the real Organization XIII. He controls ice and uses it to command storms and blizzards, freezing his opponents solid, while defending himself with his massive shield. Vexen was the highest-ranking member of the Organization inside Castle Oblivion, but ironically was the first Organization member to be eliminated. He created the Riku Replica and uses the Replica to carry out several experiments on Riku and Sora. Despite his reconstruction as a complete being, Even opted to become a reserve member of the real Organization XIII as Vexen after being approached by Saïx to complete the Replica Program for their plans. Through his research, Vexen was able to finalize his work on the program, which yielded to the creation of replicas nigh-perfect enough to become full-fleshed humans. With his work complete, he sought to atone for his past misdeeds, first by saving his master Ansem the Wise from the clutches of Ansem, Seeker of Darkness in Twilight Town, and later tasking Demyx to deliver one of his replicas to Ienzo for the resurrection of Roxas. After the defeat of Master Xehanort, Vexen willingly reverted back to Even.