Runes, Formations, and Arrays.
There were many professions that one could learn. For example, one could become a blacksmith, one could become a cook, one could become a beast tamer, one could become a cook, and one could become a businessman.
Becoming a formation, array, or rune specialist was a profession most without a talent or affinity for runes would choose not to learn despite the benefits it had.
Unlike blacksmiths where one could try their hardest to learn by repeatedly forging weapons, learning runes, formations, and arrays was harder.
Corey had no idea if he had a natural affinity or talent for runes, but what he did know was that he had a cheat that could allow him to learn about runes with ease.
His Eyes of Omniscience allowed him to see runes, and his stars of consciousness made his mental capabilities extremely terrifying.