First Order Logic's Limitations

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In the wikipedia article for first order logic (which is admittedly unreliable but I'm assuming this is consensus anyway), under the "Limitations" section there's a table of statements that first order logic can't formalize. The second one is the following:

Santa Claus has all the attributes of a sadist

I'm really struggling with this one, why can't you write this as a first order logic sentence? Couldn't you just make 'attributes' objects in the domain of discourse and quantify over them? Something like this:

∀x,y,z (Sadist(x) ∧ Attribute(y) ∧ Has(x, y)) ⇒ (Santa(z) ⇒ Has(z, y))

Why wouldn't this be a correct formalization of the sentence?