With big game features- like the new PVP or the new Guild system- we prefer to release them with every 2nd patch update (like 2.0 or 2.1), while patches like 2.0.5 or 2.1.5 we use for smaller features or focusing on bug fixes, it allows us to release patches more often than we used to, which was about every 3 months.
Valkyries in Norse mythology, would gather the souls of dead warrior to take them to Valhalla.