E.G.

According to a view I find appealing, when somebody does something wrong, there are three particulars involved. There's the particular agent who's done the wrong thing; there's the particular action that they've performed; and then there's the particular wrongness of the action. That particular wrongness is a trope, according to the view I'm gesturing toward.

***

In Anna-Sofia Maurin's extremely useful SEP entry on tropes, she discusses efforts that have been made to defend the existence of mental tropes on the ground that (1) mental properties are causally potent and (2) mental properties need to be tropic in order to be causally potent. Such efforts, on Maurin's account, begin with the view that the notion of a property is really two notions, as follows:

Property₁=that which imparts on an individual thing its particular nature (property as token)

Property₂=that which makes distinct things the same (property as type)

And she explains:

Once ‘property’ has been [thus] disambiguated, we can see how mental properties can be causally relevant after all. For now, if mental properties₁ are tropes, they can be identified with physical properties₁. Mental properties₂ can still be distinguished from physical properties₂, for properties considered as types are—in line with the standard view of tropes—identified with similarity classes of tropes. When Lisa removes her hand from the stove because she feels pain, therefore, she removes her hand in virtue of something that is partly characterized by a trope which is such that it belongs to a class of mentally similar tropes.

And she says:

This trope is identical with a physical trope—it is both mental and physical—because it also belongs to a (distinct) similarity class of physically similar tropes. Therefore, mental properties can be causally relevant in spite of the fact that the mental is multiply realizable by the physical, and in spite of the fact that we live in a physically closed and non-overdetermined universe.

Here Maurin is focusing on how a tropic view of mental properties can be handy if you want to say both that (a) mental properties are causally potent and (b) only physical properties are causally potent.

But here I want to point out that a tropic view of mental properties might also (or instead) be handy if you want to say both that (a) mental properties are causally potent and (c) only particulars are causally potent. 

Note that (c) doesn't require or entail (b). Somebody who likes (c) might be happy to allow all sorts of non-physical yet causally potent stuff into the world. She might have no problem with causally potent hobgoblins, for example. Her view might just be that it's only particular things, whether they are physical or non-physical, that causally make things happen. So, e.g., the number nine can't make anything happen; but hobgoblins, at least in principle, can make things happen. Someone who held such a view, and who wanted to affirm the causal potency of mental properties, might have a lot to gain from a tropic view of the mental.

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I don't have any strong attachment to (c), but I am drawn to a structurally similar view: (d) Only particulars are normatively potent. Here is an argument to consider:

The normative potency argument for a tropic view of wrongness
(1) Wrongness can be normatively potent only if wrongness can be a particular.
(2) Wrongness can be normatively potent.
Therefore, wrongness can be a particular.

One way for something to be normatively potent (as I'd like to conceive of normative potency) is for it to be reasons-providing. That is, if the fact that X is P provides a reason to promote, perform, avoid, or prevent X, then P is normatively potent. 

If being reasons-providing is all there is to normative potency, then I think (1) is plausible (because it seems to me that, in general, all of our reasons are provided by facts about particulars). But I worry about the plausibility of (2) (because many people will say that it is moral fetishism to think of wrongness as reasons-providing, as opposed to being merely correlated with, emergent from, or supervenient on reasons-providing properties).

So, I think that in order for the argument above to be maximally compelling, I might need to come up with a broader conception of normative potency.