Densetsu no Yuusha no Densetsu anime and LN

Recently i watched Densetsu no Yuusha no Densetsu anime .
I found the story magnificent (though the anime adaptation was probably a crime) and I want to read the Light Novel.

After some search I found that there is :
The Legend of the Legendary Heroes
The Legend of the Great Heroes of Legend
The Legend of Legendary Heroes Anyway
Legend of the Black Fallen Hero

Can someone give me a clue about what is happening to each of these LN's,and where the story continues after the end of the anime?

Thank you in advance.


(Sorry if this is the wrong place to post this , but i wasn't sure.)