A "nameless protagonist" refers to a main character in a story who does not have a specific name. They are often referred to by their role or description instead. Full definition
«Authority» reveals that the nameless protagonist of «Annihilation» has «high cheekbones that speak to the strong Asian heritage on one side of her family.» (indiewire.com)
The nameless protagonist (Daniel Craig)-- call him X — has made a pile of money in drugs, established a successful realty business as a front and laundered his ill - gotten gains through the same accountant used by his boss, prosperous, aging cockney hard - case Jimmy Price (Kenneth Cranham). (tvguide.com)
The bulk of the game consists of doing quests to solve a massive mystery surrounding Edgar and the nameless protagonist. (xblafans.com)