Can Nystul's Magic Aura's False Aura option be used on creatures?

Question

This question was inspired by a question on whether detect magic can sense feign death. I believe it would, which raises the question of how you could foil detect magic in this case. The obvious solution would be use to Nystul's Magic Aura (also known as Arcanist's Magic Aura), which is designed for concealing magic.

However, as I read the spell more closely, I noticed an issue. Magic Aura can be used on both creatures and objects. Magic Aura has two options: False Aura and Mask. Mask is used to disguise a creature's type or alignment. False Aura is used to disguise whether or not the target is magical and the school of magic of its aura. Therefore, if I want to make my creature under the influence of a spell appear to not be under the influence of a spell, I would want the False Aura option.

But there is a problem. False Aura starts by saying

You change the way the target appears to spells and magic effects, such as detect magic, that detect magical auras.

Great, that's exactly what I want to do. However, the rest of the paragraph refers to this option's effects on objects, not creatures. One could read this as meaning that the False Aura option has no effect on creatures and is meant to be used only with magic items. However, Magic Aura also says

When you cast this spell, choose one or both of the following effects.

Mask clearly applies to creatures and has no benefit for objects (since they have neither type nor alignment). Thus, if False Aura only worked on objects, they would have no reason to let you use both Mask and False Aura on a single object (save for some extremely niche cases where the target could alternate between being an object and a creature). This implies that maybe False Aura can work on creatures, and they just used the object case as an example.

But there's another complication. Even if I can use the False Aura option on a creature, it is unclear whether False Aura will conceal spells which are affecting the target or whether it only disguises magic which is intrinsic to the target (such as from any creature summoned by a conjure spell). I am interested in the former case, where the target is not intrinsically magical but is under the effect of spells.

Can I use Magic Aura to conceal or disguise magical effects on a creature?

Answer 1

The likely intent is that False Aura is usable on creatures

As you say, the language of the spell allowing the caster to choose "one or both" effects only makes sense if there is a reason to use both effects on the same target. And for this to be the case, since Mask doesn't make sense for objects, False Aura must be usable on creatures alongside Mask. As for why False Aura only uses "object" rather than "creature or object", this is likely to avoid the awkwardness that would result. Here's what the wording would be in that case:

False Aura. You change the way the target appears to spells and magical effects, such as detect magic, that detect magical auras. You can make a nonmagical creature or object appear magical, a magical creature or object appear nonmagical, or change the creature or object's magical aura so that it appears to belong to a specific school of magic that you choose. When you use this effect on an object, you can make the false magic apparent to any creature that handles the item.

Also note the last sentence in the description of False Aura, which starts with "when you use this effect on an object". Like the "one or both" wording mentioned above, this limiting clause doesn't make any sense unless False Aura can be used on targets other than objects.

In summary, a literal reading would imply that False Aura has no effect on creatures, but if one assumes that the above mentioned clauses of the spell are intended to have any meaning at all, the logical conclusion is that False Aura does work on creatures.

False Aura hides all magic auras on the target, including spell auras

I've actually asked a similar question before, and the answer also applies here. The magic auras hidden by the False Aura effect are precisely the same magic auras that Detect Magic detects, and that includes the auras of any active spells on the target.