Some fantasy and science fiction novels have characters who do not like personal pronouns; they use constructions like "This one is eager to attend" rather than "I am eager to attend". What person is that considered? Is it still first, or does that make it third?
This may be called Illeism Wikipedia which is a device that refers to a first person as a third person. Julius Caesar is well known to have used this device in his writing on the Gallic Wars, and Shakespeare continued to do so in his play Julius Caesar Quora.
In English, such reference will be grammatically in the third person.
This device is used more than some of us might imagine. For example:
Bill does not care to wash windows.
When asked to wash windows he might say:
Bill doesn't do windows.
It can be a useful device, if used sparingly.