Intuition

[Reanimation] was among the most devastating abilities of a Necromancer. In fact, it was this technique that ended the Sky God Era and triggered the Shrine Era. 

[Reanimation] was a technique that could either be incredibly weak or impossibly strong depending on the way it was used. Due to this, some often called it the Origin technique of Necromancers in a facetious way. 

Though this namesake was given in jest, the more one thought about it, the truer it seemed. 

[Reanimation] could be used by any Necromancer with death qi regardless of power or strength. That was in line with how Origin techniques functioned. The only reason [Reanimation] was not considered an Origin technique was because it couldn't be used on any target. 

An Origin technique would function irrespective of who it was aimed at. Of course, its strength would vary depending on who was using it… But it would work.