They called it plundering because disciples from all the sects and even the 25 cultivation families will participate in the harvesting. At the end of the day, the secret realm would be stripped bare.
Harvesting is what the disciples of the Blood Skull sect think they are going to do. They know that they are going to a place where many people will die, but they don't think that they will die.
This is the confidence granted by strength. The only ones that disciples of the Blood Skull sect are afraid of are other disciples of the Blood Skull sect. As long as the other disciples of the Blood Skull sect don't antagonize them, they don't believe that they have anything to fear.
In general, it is considered by the disciples of the Blood Skills, etc., that the B-grade disciples of their sect are on the same level as the best disciples in other sects.
This judgment isn't based on only blind confidence. Even disciples of the Blood Skull sect can admit that there are many talented people in the other sects, and there are even some with better talent.
They can admit this, but they still think that the disciples of other sects are weaker simply because other sects don't have the power of armaments.
Apart from the various kinds of abilities of armaments, armaments double the power of their user. Because A-grade disciples of the Blood Skull Sect can use armaments, it is considered that A-grade disciples are better than the S-grade disciples of other sects.
This is the major reason why everyone on the airship believes that they are going to harvest and plunder the secret realm. The second reason is that only the secret realms of other sects are harvested, not the secret realms of the Blood Skull sect.
The secret realms that serve as the foundation of the five sects are graded as rank 4 secret realms. These rank 4 secret realms are offshoots of rank 5 secret realms above them.
Every secret realm is a root of the Ethera tree. Just like the rank 4 secret realms are linked to the rank 5 secret realms, the rank 3 secret realms below are also linked to the rank 4 realms.
In total, there are 25 rank 3 secret realms under the control of the five sects. The Blood Skull sect controls 7 of the 25 secret realms.
7 out of 25 is 28% of the available secret realm. It is more than one-fourth of the available secret realms. But the Blood Skull sect doesn't stop there.
The Blood Skull sect doesn't share their seven secret realms with other sects. But disciples of the Blood Skull sect can participate in the harvesting of the other secret realms.
This is another piece of information that he learned from the conversation going on around him. It reminded him of what Elder Calcetti had said about the Blood Skull having the largest territory and would have had more territory if not for the fact that they don't have a need for it.
Now Arthur knows why the Blood Skull sect doesn't need to expand their territory. It is because the other four sects have been very cooperative.
He chuckled and thought to himself, "Very cooperative."
When he thinks of the word "cooperative," he is amused. He is amused because he thinks that calling what is going on a cooperative arrangement is an understatement.
It can be said that the Blood Skull is squeezing the resources of the other Blood Skull sect. If the word "fleecing" were to be used, it would have worked too.
But after being amused, he also has to admit that this is the kind of arrangement that can work for everyone. He can already tell that things will be worse if the Blood Skull doesn't get what its strength deserves.
He thought to himself with a smile, "This is the sort of cooperation that can make the Blood Skull sect require a reason to wipe out a cultivation family."
This arrangement and the fact that the secret realm that they are going to is being controlled by the Sword Way sect made him remember Orga and the Edwin cultivation family, who were disrupting the business of his dojo.
He was reminded of his threat to Orga and how easy it would be to bring that threat to fruition. It seems Orga also recognized the authenticity of the threat because Arthur hasn't heard any more disruptive news about him.
He chuckled to himself again and returned to working while listening to the conversations around him. Meanwhile, the airship sailed through the air as if it weighed nothing.
There were many such airships flying towards the territory of the Milton cultivation family in the kingdom under the control of the Sword Way sect.
Each sect brought 1,000 disciples at the second mortal coil and 3 elders at the third mortal coil. Only the Sword Way sect brought 2,000 disciples and 6 elders. This was the benefit of being the owner of the secret realm. They get to bring twice as many people in order to earn more.
So in total, there would be 6,000 disciples from the sects. As for the 25 cultivation families, each one would bring 40 people, which makes for a total of 1,000 people.
40 people each seems like a small amount, but it is more than enough for the cultivation families because they don't have up to 40 people at the second mortal coil who are at the peak of the second mortal coil.
In fact, some cultivation families don't have up to 40 people at the second mortal coil. So they usually sell the slots for the secret realm to loose cultivators in order to make up the number.
In total, there would be 7,000 people at the second mortal coil and 43 elders at the third mortal coil entering the secret realm. This many people entering the secret realm is why the process is called harvesting or plundering the secret realm.