I always prefer my 90s books so I haven't checked if Ultimate/Revised mage any changes here.
The sensitive psi of Sense Magic (Rifts page 123) talks about magic energy, but I sorta overlooked it because I never got to play much of an investigative game and when that stuff came up it was usually Hound/Stalker territory.
It does mention you can pinpoint a particular person (or place/room/object) and even invisible "magical supernatural creatures" can still be approximated to a general area.
What made me think more about this power was this blurb in the 'Vampires Versus Psionics' section on page 34 of Vampire Kingdoms. Under "Psionics that affect Vampires" the end of the first paragraph:
Sense magic will not indicate a vampire, they are not considered creatures of magic.
The implication here is that SM will indicate things which are considered creatures of magic. So for example it would let me know that there is a Dragon (page 37) Flooper (page 132) and maybe Oltec (page 150 says 'magic creatures' not 'creatures of magic', so it might be different) or an Elf (Atlantis 35) or Changeling (as of PF2)
Knowing that SM can indicate a CoM doesn't necessarily indicate the context of WHEN or HOW it indicates them though. While men of magic are indicated as being creatures of magic (Conversion Book 43) the Sense Magic power says in parenthesis at the end "users of magic do not radiate magic energies until they call upon them".
That may only apply to practitioners of magic who are not creatures of magic though (like women of magic) because otherwise, there would be a lot of Creatures of Magic who are never sensed by Sense Magic because they don't actually call upon any magic abilities. But creatures like Bug Bears (Conversion Book 111) mention under Magic "None, other than natural abilities. Also radiates strong magic and has a magic aura similar to a brownie"
These might be 2 separate things. Maybe a Brownie's aura alone isn't vulnerable to Sense Magic, perhaps the 'radiates strong' is a BugBear-exclusive trait overlapped on top of a Brownie-ish aura so SM senses them but not Brownies?
Getting back to vampires, I figure that while they are supernatural creatures, they are not normally 'magical supernatural creatures'. I think the exception would be vampires who were previously of a Practitioner of Magic OCC, such as Esteban Morocco (page 140). Since he is both male and a Practitioner of Magic that should make him a Man of Magic and thus a Creature of Magic, meaning he is both CoM+Supernatural Being like dragons are (page 37).
Does anyone know any other CoM/Supernatural combines like dragons? I'm interested in knowing what races can hurt vampires with unarmed attacks. I used to assume anyone with supernatural PS could, but I think I jumped to that conclusion without proof. Although perhaps a later book like Nightbane, VKrevised or Rifts Vampires changed that and expanded what could threaten them?
I would assume that Nightbane could for example hurt a vampire with a punch, and it probably says that somewhere, but I don't know if that's due to supernatural strength or because a Nightbane in Morphis is considered a Creature of Magic / Supernatural Being combination like a dragon is.