Re: Nem measuring scale
It's not like the Hyakushiki Kannon had no "drawback" so to speak when casting it. Hyakushiki Kannon is just like Jajanken in that there are some preparatory stances Netero had to go through before he's able to unleash the actual attack. This preparatory stance enhances the attack strength, as in the "risky" stances and shouts Gon makes before releasing either Guu, Paa or Chii. Meryem, as he is still a nen noob, does not understand why Netero had to do these stances. He saw this as a risky and probably stupid gesture when involved in a high-speed battle of life and death. For Netero, it allows him to express his gratitude to martials arts. This makes him more psyched about the attack and therefore his attack comes out more powerful. We all have seen the increase in strength of Gon's nen when he completes his phase of stances and shouts. This has been grasped by Knuckle and Morau, respectively. This will be the case with Netero's string of gestures. Therefore Netero does not really need a huge amount of aura to inflict a lot of damage because of this aura-enhancing string of gestures that is independent from the user's Aura amount. It's like a damage multiplier one gets when one puts restrictions and conditions on one's Nen ability, as in Kurapika's, however this one is less desperate and took the longer route as it went through a long process of training and perfection. We also need to consider that Nen is dependent on the user's psyche. Netero was in a state of pure concentration and total bloodlust in his fight against Meryem and that is a good cause as to why his Nen amount probably got a boost. It's a decent excuse for the age-old manga/anime cliche that characters gain a sudden increase in power in battle, however this is subtly explained by Togashi, therefore we cannot dismiss this as "ass-pull powerup" mentioned by a lot of disgruntled yet unenlightened HxH readers in this current arc.
It's just that since Netero has trained himself to the point that his gesture phase and actual attack launch is faster than the speed of sound, that there's actually no risk against most enemies. However the risk factor amped up against Meryem and therefore the damage multiplier racked up as well.
Therefore Netero does not need 10,000,000+ Nen to launch hundreds of thousands of Kannonslaps during his battle with Meryem.
There's also another theoretical explanation why Netero does not need more than 100,000 nen to inflict huge damages on an opponent. Let's say the actual Kannon statue costs 50,000 Nen to create and all or some (realistically a small portion) of the nen used to create it is translated to damage on a single attack. However Netero would have to go through the gestures to materialize it (its already there however its not materialized) and attack. So he just creates the statue once, set it aside while "out of the playing field", and summons it for free by doing those gestures. So he could have the rest of his nen consumed with the other nen applications (like Ken).
In short, in this explanation, there's no summoning maintenance cost unlike Ken which needs continual (?) nen expenditure to keep running; it's a cast-once statue summoned by a no-cost string of gestures that actually boost its speed and attack strength (as explained above).
The explanation in the paragraph just above this one could be expressed in Magic The Gathering rules, but I'm just interested in the card art so I really don't know the rules and I don't know how I could express it.
