User blog comment:Yuri Rozu/Fairy Tail Chapter 508 Pleasure and Agony/@comment-3045936-20161101003941

Well this chapter confirms for me, that Rahkeid's Magic is similar to Buddhism or Shintoism.

Buddhism for example as the six realms of rebirth are the agony and Nirvana is pleasure. Rahkeid's Magic seems like a short cut, that those of good karma or (pure of heart) are immune. While those not pure of heart or sinned are in agony.

It also reflects Shintoism a bit. As among the many practices of the religion. One is to purify one's self or the inner Kami and to reject death.

Also I think he in meaning Zeref as his father, means his creator. Maybe another revived person or maybe even Zeref's and Natsu's dead father revived.