We meet Parker Robbins in the first three episodes of Ironheart. The mysterious character is introduced as a thief who uses a hood that enables him to turn invisible. However, we also see that using the Hood comes with a toll, as we see Parker's body being covered with demonic marks. Parker tries to cover these marks with a tattoo, but it is clear that these tattoos can't hide the marks.
Thus, on the surface level, it appears that the mystical hood seen in the show may be similar to the One Ring from The Lord of the Rings, where the bearer of the powerful mystical object must bear the brunt and curse of the object themselves. This is not surprising as this hood has demonic origins in the comics as well. However, Ironheart probably changed the source of Parker Robbins' hood.
Ironheart's The Hood's mystical origins in the Marvel Comics explained:

In both Ironheart and the comics, Parker Robbins is a thief who uses a mystical hood to carry out his heists. Using the moniker "The Hood", Parker utilizes this mystical artifact to make himself invisible in all of these heists. However, as the hood is of demonic origin, it corrupts the wearer. However, it is the source of the hood in the comics that's probably different.
In the comics, Parker Robbins encounters the demon Dormammu in one of his heists. There, Robbins manages to beat the weakened demon and takes his mystical Hood, which helps him get an edge over other petty criminals in the Marvel Universe. However, if the fan theories were to be true, the mystical hood might belong to the satan of the Marvel Universe, i.e., Mephisto.
The hood might belong to Mephisto in Ironheart and the overall MCU.

In the closing minutes of the second episode, we hear the Hood whisper some questions inside Parker Robbins' mind, hinting that it might be cursed. Some parallels can even be drawn between this Hood and Doctor Strange's Cloak of Levitation, both having a mind of their own. But the Hood might have absorbed Mephisto's cruelty and evil.
Plus, it seems that Parker, instead of stealing the Hood, might have summoned the devil for power, and Mephisto probably gave the former his hood. In exchange, Mephisto might have taken Parker's Soul, and the marks on his body might symbolize his soul getting corrupted.
"Set after the events of “Black Panther: Wakanda Forever”, Marvel Television’s “Ironheart” pits technology against magic when Riri Williams (Dominique Thorne)—a young, genius inventor determined to make her mark on the world—returns to her hometown of Chicago. Her unique take on building iron suits is brilliant, but in pursuit of her ambitions, she finds herself wrapped up with the mysterious yet charming Parker Robbins aka “The Hood” (Anthony Ramos)."
Ironheart will conclude next week on Tuesday, July 1, 2025, as the last three episodes stream together on Disney+.