Arc The Lad: End of Darkness is fifth game in the Arc The Lad Series.
While End of Darkness main cast is small, the party's rosters is significantly expanded by the acquisition of "character cards," which once collected can activate a new playable character hailing from previous Arc the Lad games (say the cast of Twilight of the Spirits). However, these characters cannot be used in battles that advance the plot, only in side-quests or online play.