Disclosure: I run this server.

For anyone who remembers Season 6 MU Online: Zenaria x40 keeps the classic wing ladder (1st wings at level 180, 2nd at 215, 3rd at 300) and adds Wings 2.5 at level 250 in between. Alongside the usual grind there is a Path of Hero, 200 kill quests in a row that pay zen, stones, stat points and GP. EXP x40, master x10, no wipe, free to play.

https://zenaria.ru/en/