That's where our systems of magic differ.
Barring these servants, I'd guess- my worlds' magic has no such thing as magical energy.
It's purely an extension of the minds' capabilities.
A very- very- very difficult thing to muster, but it has no real way of running out of energy.
1.5 imperial gallons of tea were consumed during the writing of this post-She keeps eating, finishing her share of the sandwiches-
What if there’s no better word than just not saying anything?-nods- Not so much... not valuable.
More- hard to do.
Its' knowing that someone has tampered- to manipulate qualities, or manipulate laws.
Like- I'd guess for us its' knowing a painting is tilted, for you- magic detection is more seeing that there's a painting there.
Because technically speaking- all things are made of magic where I'm from, because Magic is tied intrinsically to reality. It is the manipulation of what ties the world together and makes it up.
1.5 imperial gallons of tea were consumed during the writing of this post-nods- Mm. Its' purely- mental effort.
For us, anyway.
Which is why- servants are something that I'd consider impossible. And why I was sat mortified- and honestly afraid- for several days when I realized that Castor had managed to comprehend death itself.
1.5 imperial gallons of tea were consumed during the writing of this postHe probably has access to that too.
But no- he definitely abused his position as a Servant. I can see how the logic would follow for a savant.
Servants would've experienced death once before. He simply used that information- as a Servant still linked to my world- to formulate a hex using that experience to analyze.
Though he was likely killing as well- to be an outside observer. Eyes are windows to the soul, I have no doubts that a lot of the dead would've had his eyes looking into theirs when he was researching it.
1.5 imperial gallons of tea were consumed during the writing of this post

(nods) Yeah, I do. Even with the few magecraft spells I know, I have trouble keeping them active.
...Why keep yours on for so long, though?