The plot and atmosphere in the Heroes series ran out in the original two games.

Lol. "The Price of Loyalty" has nothing to do with Might and Magic. What was absurd and copied in the plot of the third game? And most importantly, where was it borrowed from? The plot in the fifth game is a complete borrowing and plagiarism from such universes as Disciples, Warcraft, and Spellforce. Plus, stereotypical fantasy plot devices (some of which were borrowed from the third game).
There's no need to try to dismiss other people's arguments with the canned phrase "the second Heroes game is the last game with a decent plot." By the way, besides the Heroes series, the Might and Magic world has other games that are directly related to the Heroes in terms of plot. They also have an atmosphere and plot that no game in the HoMM series can compare to.