Legend of the Invincibles
Legend of the Invincibles is an add-on campaign for the game Battle for Wesnoth. It adds a massive campaign, about 200 scenarios long. The campaign has largely tweaked game mechanics, mainly expanding the RPG part of the game.
The author of this campaign is Dugi (due to name uniqueness, the name is spelled as Dugy on GitHub). The address of the git repository is https://github.com/Dugy/Legend_of_the_Invincibles. The forum thread discussing the campaign is at https://forums.wesnoth.org/viewtopic.php?f=8&t=32384. If you wish to discuss anything, go there.
The add-on is usually downloaded from the game's add-on server. If you wish to use the version from GitHub, look at https://wiki.wesnoth.org/EditingWesnoth to see how to use it.