|Name:||The Colder Side of Choice, Purity and Sin|
|Episode Number:||Episode 4|
|Opening:||Ao Shinko "Blue Faith" Lyrics by ZeroXEbony|
|Ending:||Soul Devotion, Lyrics by ZeroXEbony|
|Season:||Verse 1: Purity and Sin|
|Previous Episode:||Foreshadowing Horizons|
|Next Episode:||Nestled Hope, Catch 22|
The Colder Side of Choice, Purity and Sin is the fourth episode of Control Sequence and is the fourth episode in the First Season of the series. It saw the introduction of several new characters, including Reiga's partner Azure Interface Primefield Akari "δ Four" and the Asassin Kiryos Hikamigawa.
- Reiga Sorairo
- Akari - First Appearance
- Kiryos Hikamigawa - First Appearance
- Siegfried Schtauffen
- Myri Kukiyona
- Lazarith - Mentioned
- The NOS attacks Rau's home where Nex was residing for the night resulting in Nex becoming angered as he recalls the government's involvement in crushing every home he used to have, resulting in him killing several of the soldiers out of rage.
- Rau informs Nex that Imyo was prepared to give everything to ensure Nex lived, and he believed in him that he'd be one to change things. Though just what Imyo or Rau might of known isn't said because Nex is told to head back and look for Myri while he dealt with the soldiers.
- Kiryos Hikamigawa is introduced, as he tries to deal with Nex who rushes off, Nex bests him in combat and then seems to have resolve to kill him until for some reason Nex decides to let him live leaving the question "Why" for Kiryos to ponder on.
- Myri is the girl which Nex was looking for apparently, as he storms in without warning and tells her that she's one who holds power in her soul the NOS both seeks and, she can help him destroy the NOS.