It is said that the Aferian is Grade 2 Ruin which had appeared two times before and only half of it has been explored while the others half remain unexplored.
As for what type of Ruin is Aferian Ruin, it is not mentioned in the free information.
Exploring ruin is a very dangerous matter, many people lost their lives inside it.
There are many forms of danger's exist inside the ruins form the runic restriction to dangerous monsters but they are not the biggest danger there, the biggest danger in ruins is the Grimm race.
Grimm race can also travel to the ruins, like us they could also connect to the Ruin and due to them the advance knowledge and resources, their members always greater than us.
That is why every time when ruin opened there is always a huge bloodbath that occurred between the human race and the Grimm race, no one wants others to gain anything from the ruin.
