"lack of rulers = decentralization"
Anarchy has nothing to do with lack of "rulers". It's about lack of centralized governance.
A voluntarily appointed ruler would not necessarily contradict with Anarchist ideals.
Whatever, you have no clue what you're talking about.
Please read this: https://en.wikipedia.org/wiki/Anarchism
RE: Anarchism Exposed: Part 1 - Clarifying my stance and defining Anarchism