That makes it seem unlikely we’ll get to see Mr. Hyde in the flesh, although who knows what tricks The Mummy has up its bandages.
This does point towards Jekyll filling a Nick Fury role in the series, with The Prodigium almost acting as S.H.I.E.L.D., bringing together the disparate monsters into one big story. While it’s not what Robert Louis Stevenson probably had intended for his legacy, it makes a lot of sense for the character’s involvement here; having a slightly stronger evil side doesn’t match immortality or becoming a literal wolf. “If we’re going to bring in Henry Jekyll, how is bringing Henry Jekyll into the mummy story not detract from the mummy story?
How does Henry Jekyll become part of this story in an organic way?
Bringing in such a big character into a separate movie could easily feel like simple franchise-bait and ring cynical, so this concern being addressed at his introduction is refreshing.