{Harry's temporary room, Leaky Cauldron}
"Nox~" I said with a downward wand movement, extinguishing the bright light glowing at my wand's tip. I had gained a lot of understanding about how magic works and why the whole canon revolved around wands.
'Strictly speaking, I'm nothing but the mana battery in the simplest terms,' I concluded. Whenever I focused on a spell and did the correct wand movements and enchantments, the wand took the mana I pushed through it to cast the spell, and it was like a black box that converted that mana into a spell.
So my wand movements, intent, and chant are simply instructions fed into a black box, and in exchange I get a spell. The only reason that the Nox spell exists and people don't just simply stop feeding the wand mana to stop the spell is that the previous instructions are saved in the wand, and the Nox spell is needed to reset the charm.
'Without the Nox spell, as long as I feed mana into the wand, it will forever generate a white light. But I could theoretically cast a different set of wand movements and enchantments to feed my wand a different set of instructions, and that was another way to cancel the spell.' I concluded.
As for the 20% chance of success, it was the chance the spell would work if I wasn't concentrating my intent and was just doing the wand movement and the chant. In case even one of those three instructions were missing, the chance for the spell to fail or even go wrong increases.
'So if I focus my intent along with the wand movement and say the spell incantation, the spell works almost every time. If I focus my intent and wand movement without saying the spell, it works only 20% of the time. If I only focus my intent to cast a Lumos but do not do any wand movement or say an incantation, then the spell hasn't worked once in the 10 or so tries.' I thought as I summarized my experiences, I had half a mind to write this down before I gave up on that.
'I was never really the note-taking kind of guy. Still, with my mana almost down to single digits, let's wait for it to recover. Then I'll try and learn the Levitation charm.' With my plan set, I shifted my attention to the new and improved Lumos spell that had leveled up during the experimentation session.
'What is annoying is that the failed casts still cost MP, but at least that tells me it should be possible to cast a charm with just intent. The odds of success, though, should be very low.'
...
[The Wand Lightning Charm Lv 1 (87/100)]
[Incantation: Lumos]
[Spell Cost: 0.5 MP/s]
[Spell success rate: 30%]
[Wand movements: Flick upward and point]
[One of the most basic charms and the modern version of the illumination charm that can be used to look at your surroundings when stranded in complete darkness]
...
...
[The Wand Dousing Charm Lv 1 (83/100)]
[Incantation: Nox]
[Spell Cost: 0.5 per cast]
[Spell success rate: 30%]
[Wand movements: Flick downward and point]
[One of the most basic charms and the counter charm to the modern version of the illumination charm that can be used to stop the Wand Lightning Charm]
...
It also made sense why only a few people were able to do wandless magic, and even if they did, why only with a few spells and not all the spells that they knew. Even if you managed to figure out how your wand translates your mana into a spell, learning that knowledge for every spell just doesn't seem possible.
'In the movies, Voldemort was able to make Harry bow with a hand gesture, but that could be attributed to theatrics. I have read the books, but I don't exactly remember if anyone overtly even performed wandless magic or not.' I thought as I looked at my status once again, confirming that my MP regeneration is very slow, around 2 per minute, so it would take me around one and a half hours to go back to full mana.
While I was debating what to do, I heard several hard knocks against my window. I looked up into Hedwig's beady eyes as she stared at me to hurry up. I quickly walked over and pulled up the window as she held out her beak, showing me a letter clasped in her mouth.
I took it hurriedly as I brought some of her snacks out of my inventory and placed them on the windowsill. Ignoring the bird, I looked at the neat handwriting on the front. As expected, it was written with a pen instead of ink. I tore open the envelope and quickly read through her response.
'''Hello Harry, Good morning.
I don't know if the letter can reach you, as you didn't give me a return address, but I'm currently in Diagon Alley because I brought my parents in to show them the magical world. We can meet at the ice cream shop at Noon if you have time. My father wants to talk to you about the money.
See you there,
Hermione'''
I looked at the old clock, which showed it was almost half past 11. Grabbing the change of clothes that I had bought, I quickly hopped into the shower.
...
...
Changing into clothes that fit my body, I looked down at my somewhat frail arms in wonder. How on Earth I managed to hold Adorabella up last night was a question I couldn't answer. Looking at the mirror, I waited for it to comment.
"You need to handle the mess on your head, scruffy."
'Yeah, I don't think that's happening,' I thought as I clawed through the front of my hair, not really intending to tame that mess, as I had already tried it in the morning and swiftly walked out of my room after closing the door.
...
I walked through the lively alley and noticed a fresh batch of students running around, rummaging for supplies, while I kept my eyes out for any familiar names as I arrived at Florean Fortescue's Ice Cream Parlour.
I spotted Hermione with Mrs. Granger, animatedly talking about something. A middle-aged man with rectangular glasses sat with them, engrossed in reading through a magical book. He had that nerdy look about him.
"Hey Hermione," I greeted, and the brunette turned toward me with a wide smile, waving me to sit down excitedly. I checked her out briefly. She was wearing a dress like Susan's yesterday. Clearly, she paid more attention to detail than her canon counterpart and had learned to blend in. My eyes drifted briefly to her cleavage, but I didn't check her out for long and focused on what she was saying.
"Guess what I found, look." She pointed excitedly at the open book in front of her, to a page that mentioned my name.
'''Numer 21: Harry James Potter(1980- Present)'''
AN: That's the gist of it. Harry might gain an ability later that lets him sense mana around him; only then will I elaborate on this black-box system and focus more on how magic works alongside Harry.