It's just a meteor right? Brandish has shrunk things that size before.
Mass is not proportionate to power.
Irene had to tap into the magic power she could access in her dragon form to be able to cast Deus Sema.
It was a master enchant that was, and probably still is, the strongest form of enchantment.
Brandish had never shrunk something of that magnitude in power before.
MP doesn't equate to durability though, otherwise the rest of the spriggans would be as frail as Neinhart.
As for being a master enchant, I have no doubt that it's a greater enchantment than what Neinhart got, what I doubt is that it has more power than Neinharts MP+his enchantment, in fact I find it hard to believe it's greater than Neinharts MP alone. As strong as August and Eileen are, I'd say it's unlikely that they have more power in a single attack than a spriggan has in their entire body.
You don't have to have more power in an attack than their entire physical body to put somebody down and out.
We damage something when the force behind a motion is greater than what the target can withstand.
A brick does not have the same volume and energy as me. But if you picked the brick up and swing at my head to club me with it, you would likely deal a fatal blow because the force behind the attack is greater than what my skull can withstand, thus causing blunt trauma to my brain.
I agree MP doesn't equal to durability. It doesn't matter how great Neinhart's MP was after he was enchanted. It's a non-factor. Even if he has more MP than Deus Sema, there is nothing Neinhart has to defend against such a powerful enchantment.