A System Holder, my eyebrows couldn't help but wrinkle a bit.
Systems are identical to status, the only difference is that the system is all of the divine or chaos power which belongs to a God of a Devil.
When a deity doesn't want to live anymore and wants to pass on his position then he or she can become a system. After losing their will, the system will travel through many dimensions and worlds to look for the perfect person suitable for it.
It is just like giving away divinity, just that if one wants to form a system then the God needs to die along with his soul.
System Holders were quite rare since no one would want to die along with the Soul hence people preferred training their disciples and passing away their divinity or chaos energy when they were deemed ready.