Difference between Heir Presumptive and Usurper

HEIR PRESUMPTIVE vs USURPER: NOUN

Someone who will inherit only if no better choice for an heir is born.
See heir apparent.
An heir who stands to inherit the estate, title, or office of an intestate ancestor, but whose claim can be defeated if a relative who is closer to the ancestor is born prior to the ancestor's death.
A person who expects to inherit but whose right can be defeated by the birth of a nearer relative

One who usurps.
One who usurps; especially, one who seizes illegally on sovereign power.
One who usurps; one who seizes power or property without right: as, the usurper of a throne, of power, or of the rights of a patron.
One who wrongfully or illegally seizes and holds the place of another

Succession, Peacock throne, Kingship, Dynastic, King, Prince consort, Princeling, Monarch, Figurehead, Prince regent, Coronation, Heir, Successor, Throne, Heir apparent

Succession, Peacock throne, Kingship, Dynastic, King, Prince consort, Princeling, Monarch, Figurehead, Prince regent, Coronation, Heir, Successor, Throne, Heir apparent

He is the son of Eliwood, the main character of Fire Emblem: The Blazing Blade, and heir presumptive of Pherae.
Frenchman, that he is not heir presumptive to another crown, and that he has previously taken the civic oath.
Prince Albert became King George VI and the young Princess Elizabeth became heir presumptive to the throne.
Known as "The Brat" in the Heraldic Circle, the Heir-presumptive lives up to her nickname.
Roger was made lieutenant of Ireland and was declared heir presumptive to the Crown.

But indeed there was no need to egg the usurper on.
The first usurper, Amenmesse, carved his signs a little more shallowly.
This put Adonijah in the role of a traitor and usurper.
Tonight, a usurper rises from the ranks of trusted noblemen.
He is, however, a usurper, having no property rights here.
Pilferous wheedling finagler, plunderous pillaging usurper, longevous loquacity lottery.
By 1824, the Mokwena usurper had relocated to Molepolole.
DISCRIMINATION AGAINST AMERICAN COMMERCE BY THE USURPER OF MEXICO.
Divinity and so the usurper is said to divine.
The fourth was considered to be ah, usurper.