Father Juliano Colegui is a Roman Catholic priest and Robin's former guardian, he is also her maternal grandfather who raised her from birth. In the beginning of the series, Robin mentions that his powers have diminished, suggesting that he was once a craft user for Solomon, although it is never stated what his specific craft was.

Since he and Robin are related, it's probable that he was a fire craft user like Robin. He visits Robin in the latter part of the series to inform her about the events surrounding her past. During the times Robin stays with Nagira, he is the one who asks Amon to hunt Robin, for fear that she wouldn't be able to control her powers as they grew stronger.

Later, in "Redemption Day" he confronts Robin himself, and sees that she has not changed, nor turned into the monster he feared her to be. He asks her forgiveness and blesses her, giving her the information taken from Todo's journal that will help her choose her path, and entrusts her to her own destiny, knowing she will choose the right actions. He is voiced by Masane Tsukayama  (Japanese) and Tom Wyner  (English).