Abhisankhāra-māra - The Karmic force Kleśa-māra, or Ma̋ra as the embodiment of all unskillful emotions. Mṛtyu-māra, or Māra as death, in the sense of the ceaseless round of birth and death. Skandha-māra, or Māra as metaphor for the entirety of conditioned existence. Devaputra-māra, or Māra the son of a deva (god),
that is, Māra as an objectively existent being rather than as a metaphor.
Apart from your internal mara and metaphysical maras.
The Mara as existent beings are essentially gods with Wrong Views and Wrong Intentions.
The Mara that tempted Buddha in particular, was a god from one of the highest heavens Paranimmita-vasavatti, the devas with the power over other's creations.
That is not only can they create anything to fulfill their desires, but other create it for them to worship them.
Seeing that the Desire Realm was so enjoyable and pleasurable, why should anyone seek to leave it and so try to oppose the Buddha.
So how did such a being came about?
Through their former karmic merit.
Like gods who attain heaven but then squander their merits, maras went further by obstructing others in their search for virtue and truth.
Unlike the Christian devil, Maras are not rulers of Hell.
But in a sense they are 'fallen' in spirit, though not in power.
Eventually such a being use up their good karma and fall possibly even the the hells themselves.
Of course they are not unredeemable either, if they repent and support the truth, the label 'Mara' would not apply to them.
There is a saying in Chinese Buddhism, to cultivate karmic rewards without cultivating wisdom
is the Way of Mara.
That is your good karma could bring you high up in the the heaven or as a ruler (or someone in position of power), but without wisdom - and therefore ethics, you could easily abuse your powers, causing suffering on others and ultimately yourself.
So as you can see, you could be your own Mara, you could be a Mara to others and discourage them from doing good deeds.
buddhism.stackexchange.com/users/8238/Yinxu
The current Mara was Mara Dusi's nephew back in the days of Buddha Kakusandha.
So it seems that there's a waiting list in the Paranimmita-vasavatti heaven.
There are some people in the world who do a lot of worldly good deeds, but they dislike and discourage meditation, listening to the Dhamma, getting ordained or anything that has to do with ending of Samsara.
I would imagine such people might be born in the Mara-clan of the Paranimmita-vasavatti realm, if they can amass enough good Karma.
Among them, whoever is the most powerful, takes up the title.
buddhism.stackexchange.com/users/111/Sankha Kulathantille
As answered by Yinxu, the term '
Mara' is used in many ways in Buddhism.
I think to develop theories about Mara the Tempter , it is useful to understand 'gods' ('deva'), who include human beings with psychic powers, that Judeo-Christianity calls 'angels'.
In Judeo-Christianity, the Bible reports angels & also prophets such as Moses & Jesus that displayed supernormal (psychic) powers.
These angels & prophets are created (by nature) to rule & guide ordinary people.
These angels & prophets teach people to believe in 'God' & 'self'.
These angels & prophets with psychic powers exist today within Christianity.
Yet they are not interested in or believe in Buddhism because they believe Christianity is best for ordinary people.
Hindus are similar, often strongly opposed to Buddhism because of its teaching of anatta & atheism.
Therefore, Mara does not necessarily have to be an intrinsically evil being that is tempting people to do evil in the way Christians depict.
Satan does not exist in the Old Testament apart from in the Book of Job, as an angel in heaven with God.
The Christian idea of Satan is obviously very similar to that in Buddhism but their own version.
My point is Mara can be any being with supernormal powers that opposes the Buddhist teachings because Buddhism teaches anatta (nots-self).
Such a Mara does not necessarily need to be intrinsically evil.
Karmically, they simply need to act with the good intention that the Buddhist teachings of anatta are not beneficial to the majority of people.
Therefore, their karma will not necessarily result in a loss of their supernormal powers since opposing Buddhism is not inherently bad karma for them.
Or less insidiously, such Mara may simply be testing the Buddhas & arahants.
buddhism.stackexchange.com/users/8157/Dhammadhatu
There are no stories within the Pāli canon that I know that describe how one becomes a Mara though there are accounts of others who have been maras in a previous life
(Moggallana being one of them.
See MN 50 ).
There is also a sutta in which the Buddha declares that it is impossible for a woman to become a Māra (See MN 115 § 15).
The Buddha does explain how one can become a deva [of the gandhabba order] in SN 31.2 .
I don't know that the doing the opposite would direct one to becoming a Mara.
buddhism.stackexchange.com/users/8247/Rks1157
Mara is the most powerful being in all the sensual realms, He resides in the highest sensual adobe called paranimmita-vasavatti.
where one day is equal to 1600 earth years.
It is not easy to become Mara, Through shear will power one has to observe the precepts well & practice generosity .
Mara being the highest sensual being surpasses all the other devas in the heavenly realms in the following ways (Exceeds in Life-span, exceeds in beauty, exceeds in sensual pleasures, exceeds in glory, Exceeds in power).
Mara surpasses all devas with respect to Life-span, unmatched beauty etc... due to the fact that in the previous lives he has abstained from killing, Stealing & sexual misconduct & Drinking.
All Unwholesome actions done involving the body.
This is the reason he surpasses all other devas in life, beauty, power etc..
There is one sutta in Tibetan Buddhism, says - That Mara has the most largest & most powerful demonic army in the 31 planes of existence at his command.
This army consists of 10 regiments with powerful/hideous demons, it is said that this army weighs 10x times the weight of the earth.
It was because that some one has observed the precepts & practiced generosity**(wholesome karamic effects)
** in a massive scale but haven't listened & thought about dharma (wisdom), this is the reason to become mara.
buddhism.stackexchange.com/users/13616/Shalani
I am not asking for an explanation on the whole "What is a Mara?" question. What i'm asking about is the being mentioned in Buddhism who has the command over all normal beings, the one who came personally to challenge,frighten lord Buddha.  Is there an explanation to why or how a person become's a "Mara"?
How does one become a "Māra"?
buddhism.stackexchange.com
<sutras><realms><mara><heavens>
buddhism.stackexchange.com/questions/15121
buddhism.stackexchange.com/users/7141/Theravada
Like gods who attain heaven but then squander their merits, maras went further by obstructing others in their search for virtue and truth.  That is your good karma could bring you high up in the the heaven or as a ruler (or someone in position of power), but without wisdom - and therefore ethics, you could easily abuse your powers, causing suffering on others and ultimately yourself.   Like gods who attain heaven through their former karmic merit but then squander their merits, maras went further by obstructing others in their search for virtue and truth.  In this position and without wisdom - and therefore ethics - you could easily become a mara by abusing your powers, causing suffering on others and ultimately yourself. 
Maras are made through their former karmic merit. Like gods who attain heaven but then squander their merits, maras went further by obstructing others in their search for virtue and truth.  In this position and without wisdom - and therefore ethics - you could easily become a mara by abusing your powers, causing suffering on others and ultimately yourself. 