User blog comment:B214/Season 3 discussion/@comment-24098614-20150419010048/@comment-24098614-20150419012401

This will relate to Season 3 in a big way remember season 3 covers volumes 5 to 7, and volume 6 has a very important scene that nearly cost the life of Issei because he uses Juggernaut Drive because the original Juggernaut Drive that Issei uses drains him of most of his lifeforce leaving him with only a 100 years of Human life left.

This event alone makes Issei take another path to use this power by changing his dreams and desires, and thus altering the curse that the past users of his Sacred have used before so in a way his lust saved him.