Master Class: Cantripothurge (SF)

From the introduction:

You are drawn to understand the true nature of cantrips. While many modern spellcasters dismiss cantrips as “0-level spells,” and claim they are so minor that it takes little effort to ingrain them deeply so they can be cast endlessly without loss of energy, you believe cantrips are something very much different than “minor spells.” To you, cantrips are a different thing from spells altogether, instead representing an older and more reliable form of eldritch power than can be permanently gained by altering your connection to the power of magic, as fundamental a change as if you grew wings and learned to fly.