Scholars have defined the “magical Negro” as the Black character in the film who uses their magical abilities to help the white protagonist achieve their goal. The issue with this trope is that it frames the Black character through the white lens.
Halloran has (and was written as having) the same mental abilities as Danny, and he absolutely saves Danny while sacrificing himself in the process.
taken from : https://confluence.gallatin.nyu.edu/context/interdisciplinary-seminar/the-magical-negro-trope-in-literature-and-film
In this image · No.26
The Magical Negro is a supporting stock character in American cinema who is portrayed as coming to the aid of a film's white protagonists. Magical Negro characters, who often possess special insight or mystical powers, have long been a tradition in American fiction. This underlines their message that a "magical black character" who goes around selflessly helping white people is a throwback to stereotypes such as the "Sambo" or "noble savage".
A16, A19
Halloran is shown to have a deep connection with Danny, which is necessary for Danny’s survival: A48
Halloran is concerned about Danny and goes out of his way to save him:
A49, A52, A56, A58, A60, A61, A70
Halloran sacrifices himself:
A72:Image 1736-Image 1739-Image 1742, A83:Image 1881, A89:Image 2117
(even has him going through the same pathways as Wendy)
A76, A78