This article's title is uncanonical and a fan created one, because an official term or name has not been made yet.
Ico's father is a deadeye lightspren on Roshar. He was bonded to a Radiant before the Recreance, and was "killed", becoming a deadeye, when his Knight betrayed his oaths.
Ico refers to him as his father, but the nature of familial relationships among spren is not fully understood. Ico keeps him locked in the hold of his ship in Shadesmar to keep him from wandering off in an attempt to find the human that wields his Shardblade corpse in the Physical Realm. The fate of his father seems to have made Ico skeptical that a human such as Adolin could have any true regard for a deadeye spren such as Mayalaran.
- Although Ico's father is trapped on his son's ship, he can be summoned as a Shardblade regardless of his location in Shadesmar compared to the location of his wielder in Roshar. There are some minor side effects if they are far apart (such as a slightly longer summoning duration) that may be explored in future books.