User blog comment:Crimson and Darkness/Volume 25 discussion blog/@comment-32252462-20180330090439/@comment-30048084-20180330172349

The reason Samael isn't in the top ten is because his poison only effects Dragons, dragon type sacred gear possessors and other snake-related beings.

The top ten are the beings are based on the idea of overall meaning that their abilities can be used on everything not one single target.

or better yet think of the top ten beings as Nukes, Samael on the other hand is more like a precision guided missile.