My guess is that if they wanna break the loop of the curse, the fmc (jesus?) should be killed bf she kills her child, and the pop (ignis) should die bf he kills his lover (the mc of this life) as the procreator said to the fmc (bc they both can't die bf their beloved people die in their previous lives).
My next suspicion is whether the son is the procrastinated g** father (sorry I forget his name) that the procreator (the novel author) put into his novel to eliminate the curse, or is the very procreator bc he also was cursed to kill his parents in his next lives.