Mirror World
Alexey Osadchuk
Mirror World is a Russian LitRPG series set in the virtual world of an online MMORPG. Oleg (later Olgerd) joins the game not for glory but to earn money for his dying daughter's heart surgery, starting as a mine laborer and rising through the game's ranks, citadel defenses, clan wars, and the colonization of No-Man's Lands across five volumes.
Progression: Classic VRMMORPG LitRPG advancement: the protagonist levels, grinds skills, upgrades armor and gear, and grows from a mine laborer into a major player. Later volumes center on gaining strength, top-level monsters, clan warfare over new territory, and power progression through game mechanics. Verified via Goodreads LitRPG genre shelving and per-volume synopses mentioning grinding, upgrading armor, gaining strength, and top-level monsters.
Goodreads
