My Thoughts and System and World Background.
Right so the magic system of this novel.Firstly, you must know the people in this novel do not just break through ranks by just meditating and eating some random all powerful fruit.This is summoners novel and the only way to raise your rank is if the Summon and Summoner has have a close relationship trust and so forth.However,emotions can not be measured or ranked.For instance, a person or beast may have an excellent relationship with each other.But they are hiding some sort of dark secret or hidden emotions that doesn't allow them to go on in rank. Some other things will be explained throughout the story can't spoil much.
Ancient
Primordial
God
Demigod
Mortal
Ant
I will not explain any of those.They all VERY significant to the plot.
World Background.
First Era-The time period this took place was during the medieval times.The Church opened a portal to see their god.However,their god was angry with what they have done and cursed the descendants of the Church members.When the god left, the residue of his mere presence caused space to weaken and every realm all nine.Armies was raised,realms were burnt, people were raped.This was a chaotic period.Legends were raised about a group of people trying to stop this war and thisis Era was ushered into a Golden age by a group of people from different realms and they were gods of that era.
Second Era-This is least known about era.We do,however, now which period this takes place.It was the early part of the twenty first century.We do know it was a period of peace until something happened, not much is known about this incident.So its called the "Blank Era" `by many.
Third-Era-Read the story.
My Thoughts
No harem straight off the bat.Not going into detail why or I might get attacked for stating my opinion happened twice.This is a highly realistic novel which I hope is realistic and no bullshit my rank is higher than yours so I can beat you.Yeah no. Battles aren't like that. There is heroine for each book except the fourth.Each novel will have volumes of either 6 or 7.This novel is 65% thought out in my head.Book 2 25%.they might be plot holes so forgive. Finally fact that all characters are relevant, well most.
Weekly Power Status
-- Power
Ranking 
-- Power
stone