Planeswalker/Igniting
Igniting(also "triggering", "flaring" or "ascension") refers to thespark's ignition, that is the process by which a sapient creature activates their latentsparkand thus becomes aplaneswalker.
Igniting (also "triggering", "flaring" or "ascension") refers to the spark's ignition, that is the process by which a sapient creature activates their latent spark and thus becomes a planeswalker.
Ascension
In Pre-Revisionist stories, planeswalkers were often sorcerers who somehow acquired the incredibly vast amount of mana required to perform the ritualistic sorcery of one's own ascension. Slaying a powerful planeswalker was one common way to acquire the necessary mana.
Sparking
Following the Mending, ascension was no longer a viable option for becoming a planeswalker, making it impossible for most wizards to become planeswalkers. A very small fraction of wizards possess the qualities needed for a natural spark. These wizards are known as embers. Usually, its ignition is triggered by a powerful, emotionally-affecting, perspective-altering life event. Ignitions are often caused by near-death experiences, though it is possible for an ember to undergo such an experience — even dying — without igniting their spark.
First planeswalk
As an effect of the ignition, the newly-ignited planeswalker planeswalks away for their first time: they are pulled to the Blind Eternities and then come back appearing to a random plane, and afterwards realizing their new traveling powers.
List of all explained ignitions: