There are four requirements for them to rank up in their pathway. The first requirement is spiritual power.
They must have a certain level of spiritual power before they can accept a second, more powerful divine flesh into their existence. If their spirit isn't strong enough, they will collapse during the process of ranking up.
The second requirement is ability mastery. Godclads don't need to master their abilities completely, but they must become familiar with their divine abilities to prevent backlash.
The third requirement is an advancement ritual. This is just a series of actions that they have to do before the divine flesh within them will allow another divine flesh to join it within their existence.
Most advancement rituals are easy. But they become complicated and elaborate the stronger a godclad becomes.
In the case of the pathway of killing, all they need to do is to kill three people of the same race. Well, the requirement is easy for them.
