At 5 dots in Life mage can change himself into anything
Overcoming the problems of imperfect Pattern-transformation, the mage can create a Pattern that carries the physical nature of a beast yet holds as well his own persona and mind. The mage can take on the shape of any creature that he desires, of any size. She can shift or revert, cure her own Pattern of undesired changes and maintain a perfect state of health in any living form as she desires.
Does it mean that mage could change himself into another creature from WoD – lets say a werewolf or vampire? Of course I don't expect to suddenly turning Quintesence into gnosis or blood points and gaining gifts/disciplines but being able to cause delirium or (as a vampire) survive without oxygen and sustain itself on blood? If so, would such mage be easily to spotted as an impostor?
What about (since the legendary lawn-furniture transformation is technically possible) changing another vampire/werewolf (I guess temporally – I doubt that with only one sphere anyone could break curse of Kain) into normal mortals and removing devastating effects of silver/sunlight?
Best Answer
No. And little bit "Yes."
The Life 5 Rote Perfect Metamorphosis, and its associated sphere trait, allows you to make a perfect modification of the living, physical form. It would, for instance, allow the Mage to turn himself into a human/wolf hybrid similar in physical appearance to any of the five forms, such as Crinos, and even shifting between them. It might also allow a Mage to turn himself into a human-esque being that feeds on blood (using a vampire bat as a model) although this would likely require far more than a typical Kindred. However, every known multi-cellular organism I am aware of requires some form of respiration to live, though for most plants this is usually carbon-dioxide instead of oxygen; and there are thriving ecosystems near volcanic vents which survive based primarily on sulfur and methane.
While this could, theoretically, allow the Mage to mimic most of the life (or unlife) functions of another creature for a period of time, evading most methods of physical identification - prolonged usage would almost guarantee discovery. How long this would take would likely depend on your GMs suspension of disbelief for scientific plausibility. Almost all forms of life require some form of respiration and non-lung methods break down at large sizes. The longest times recorded for mammals holding their breath is between 90 and 120 minutes. Almost all multi-cellular animals have some form of circulatory system and most have a heart. A vivisection (ouch!) would immediately reveal most of the methods used to evade detection.
Additionally, in the same way as physical evidence there is the issue of magical evidence. While you can mimic most of the physical effects of being a shifted Garou or a Kindred and even some of the supernatural abilities with Perfect Metamorphosis, most of their abilities lie outside this Sphere. Garou, in particular, make use of their spiritual abilities rather frequently. And let's not forget cultural evidence. A Kindred or Garou who doesn't know the traditions of her people can get into a very large amount of trouble very easily. Even being a new member of the group is not always a suitable excuse and that would assume the Mage knows enough to fake even that. After all, new people at Elysium or Moots are usually spotted rather quickly.
This form of hiding is almost entirely vulnerable to magical means of detection meant to identify specific types or classes of creatures. Again, GM determination on whether your form falls within the range of a particular supernatural detection ability. A Life 1 spell meant to detect non-humans would almost certainly hit you. A Life 1 Matter 1 spell meant to detect Vampires would likely not. Whether Sense Wyrm could differentiate you from a true Kindred is open to cosmological debate as to what, precisely, about Kindred it is that this Gift detects.
Regardless, within the World of Darkness canon many of the supernatural abilities inherent to either Garou or Kindred are not solely the result of biology. Notably, Werewolves have significant spiritual investments from Gaia that allow for things like stepping sideways, the delirium, and Gnosis. Likewise, all Kindred but the Thin-Bloods are repeatedly written in terms that indicate that they are reanimated corpses solely sustained by a combination of the Curse of Kain and the blood of others. Disciplines, basic stat boosts, and other forms of blood conversions, even healing, are also another matter as it is the Curse itself that allows this transformation.
You may be able to skirt some of the issues with Kindred without the use of other Spheres by becoming a Ghoul (at the GMs discretion, of course). However, this has some serious drawbacks including addiction and the Blood Bond.
Any physical interactions with Kindred require use of Life and Matter due to the Quintessence-infused blood sustaining the animate corpse1 and Garou require use of Life and Spirit due to their half-spirit nature2. Outside of this, how the Mage cosmology interacts with the Werewolf and Vampire cosmologies is an exercise largely left to your GM. There are intentionally a great many places where at least two of the three cosmologies line up and their interplay can lead to some fascinating campaign ideas.
Overall, its probably best to keep in mind that one of the whole points of the way the Mage: the Ascension magic system is written is to allow inventive solutions to problems. Often, things that can be handled with one sphere can be handled via a different interpretation with another. In Mage, Paradox is pretty much a high level Mage's only obstacle to Total World DominationTM. However, one rule of World of Darkness has always been immutable. You may never have two templates at once, and the Tremere are a perfect example of what happens when you try.
1Mage: the Ascension Revised Edition (WW4600); page 280, Notes: section of Young Fangbanger.
2Mage: the Ascension Revised Edition (WW4600); page 282, Notes: section of Hot-Blooded Warrior.