Runic Awakening was originally conceived, among other things, as an exploration of different kinds of father-figures.
Kyle struggles with seeing Steve as his new stepfather, resisting the thought of having more than one person he calls “Dad.” When he’s transported to Doma, he finds Kalibar, who becomes a surrogate father-figure for him. Darius is also a father-figure, as is the Dead Man…and later, Sabin tries to become a parent for all mankind.
Kalibar is the nurturing, kind, and patient mentor…the one that Kyle ultimately chooses as his surrogate father.
Darius is hands-off and gruff, forcing Kyle to sink or swim. Not at all nurturing, he teaches by doing and forcing Kyle to go beyond his comfort zone.
The Dead Man is a good teacher, but is cruel and manipulative. He cares about Kyle in his own twisted way, but is abusive and controlling.
This theme extended to the subsequent books, including the latest one: Runic Revolt.