Can a Fetch change its Catch with True Shapechanging and Modular abilities?

[Shaft]

Can a Fetch change its Catch with True Shapechanging and Modular abilities?  For example, if it shapechanges into a vampire, can it transform its Catch vs [cold iron and summer magic] into [sunlight, holy attacks, fire and stakes to the heart] and lose the previous vulnerabilities while in the vampire form?

[Sanctaphrax]

Nope. Margin note at the bottom of YS185 indicates that if they could, their Catch would be reduced to +0 in value. Which it isn't.

And for what it's worth, I don't think it's best to model fetches as having unrestricted shapeshifting Powers. Going by what I remember from the books, if they show up in a given form they're staying in that form until at least the end of the scene. Been a while, so I could be misremembering, but if I were writing them up I'd put a heavy Limitation on their Shapeshifting powers.

[lankyogre]

I feel like this is also an area where a perceptive player can realize something is not what it seems. “Wait, I just forced it in front of an open window and it doesn’t care.” Or “Why is he staying away from the guy with the crowbar?” 

[Mr. Death]

The way I look at it, shapechanging might change what it looks like or can do, but doesn't change what it is.

Put another way, if you're a Faerie using Faerie magic to shapeshift, then Faerie magic can't protect you from something that is harmful to Faeries.

[potestas]

The way I look at it, shapechanging might change what it looks like or can do, but doesn't change what it is.

Put another way, if you're a Faerie using Faerie magic to shapeshift, then Faerie magic can't protect you from something that is harmful to Faeries.

and the fact that it had fey weaknesses could be used by the players to understand what it really is

[Quantus]

And for what it's worth, I don't think it's best to model fetches as having unrestricted shapeshifting Powers. Going by what I remember from the books, if they show up in a given form they're staying in that form until at least the end of the scene. Been a while, so I could be remembering, but if I were writing them up I'd put a heavy Limitation on their Shapeshifting powers.

That makes sense with what I remember: Their Catches in the novel where based on the movie they were imitating so they had to be killed in whatever manner the fictional villain was.  Being able to change forms mid-scene to change/avoid that seems...if not cheating/broken then something that should be reserved for the most powerful (akin to how only the strongest Ramps can use their fleshmask to hide from the sun. 

Though Potesta's point about Fae magic as the source makes sense too.  I think Id rule that fundamental Catches like Iron to Fae would stay in place, but you'd also get the additional "Catch" based on the Fictional Form used.  Normal rules would apply, so a famous villain that dies by Fire would be wildly different than say a version of Zod that could only be killed by actual Kryptonite, and give you more or less points to play with on the new form.  But then Id also want to significantly limit their ability to swap out those shapes. Maybe you have to spend a scene on a marathon of all the movies of a given villain before you can *attune* to a new Form?