Draco's advice had helped Harry deal with the attention rather easily, once he'd adapted it so he could use it himself. Rather than try and deal with every reporter who showed up, he'd sent a letter to Dumbledore - as his magical guardian - to arrange an official interview so a story could go out. It had gone well, as Dumbledore had selected someone who was more interested in the particulars of the spell than in using it as a way to grill Harry about his life, goals, policies, etc. He'd answered what he could about the spell, making a point of which parts were uncomfortable or private by glancing uncomfortably towards Dumbledore, who had insisted on being present for the interview as Harry's magical guardian. Each time, Dumbledore had smoothed over the issue and redirected the conversation so smoothly that even Harry had trouble spotting what was happening when he knew what was going on. For the vast majority of the technical details, the reporter was redirected to Professor Flitwick, who was doing the primary research and experimentation with the spell to determine all that could be learned about it.
As a result of that interview being published, reporters were no longer hounding Harry and most questions about the spell were asked in Charms class. Those who continued to bother him about it were less interested in the practical or 'mechanical' aspects of the spell and more the emotional, curious about how it felt to cast it and how to get into the mindset that brought it forth. As the accidental originator of the spell, it made sense to ask him that, and he answered as best he could...especially since those who asked were kind enough to keep the discussion short if he was busy.
About the only issue Harry was still having as he headed to Charms class on Halloween morning was in trying to befriend Hermione. While sitting next to her in classes was at least getting them talking about academics, it had led to a fierce tension between Ron and Hermione which Harry didn't know how to deal with. Still, he hoped it wouldn't cause a problem during class...or at least not draw attention if it did.
Professor Flitwick stepped out from behind his desk as everyone arrived with a beaming smile on his face. "Welcome everyone!" he called happily as the door shut of its own accord. "I'm pleased to say that you've all managed to get the basics and theory under your belts, so you're now ready to learn a few practical Charms!" As that got a few cheers and excited murmurings, he continued. "Normally, the first Charm I would teach you is the Levitation Charm, which is why it's the first spell in your textbook. However, there is another spell that I feel - now I've gotten the hang of it - would be useful for everyone to attempt to learn." Pulling out his wand, he spun the tip in a circle before thrusting through the center, pointing at the ground before him. "Dematio Invocus!"
With the bang of an airburst, a crimson figure erupted from the tip of Flitwick's wand, taking the shape of one of the armors from the halls of the castle. This caused widespread gasps and murmuring in excitement.
"I am certain you all remember this spell, even if this is the first time you've heard the incantation," he offered, waving his wand briefly to make a piece of chalk write the spell name and incantation on the board, as well as drawing the wand motions out. "As you can see, the shape is not universal, and instead is shaped by the source of the Determination the witch or wizard who casts it puts into it, not unlike the Patronus Charm which it bears such a strong resemblance to."
He then grinned widely. "However, unlike the Patronus, this one is much simpler and more straightforward to create...as one of the core aspects of making spells work in general is the determination - the conviction - that they will work. As such, it is much more natural to achieve the proper mindset to generate a Dematio while still having the mindset to cast. And while it's not as versatile as a Patronus - among other limitations, it cannot be used to deliver a message - it has one particular bit of usefulness that has led me to believe it important to attempt to teach everyone the spell as soon as possible."
He then stepped up to the crimson armor wraith, which promptly knelt before raising its shield, leaving Flitwick now all but surrounded by the figure. "I am certain many of you know some offensive spells, as well as having seen a duel or two in your time. Now, whoever knows a spell one can cast at an opponent...I want you to cast it at me now." With that, he sheathed his wand, interlaced his fingers, and waited.
It took a bit before the first spell flew with a shouted incantation...only for it to disperse on impact against the Professor's Dematio, the magic dissipating in colored sparks and smoke before fading completely. Soon after, more spells flew until everyone was trying to cast something. Each spell had the exact same result as the first, dissipating on contact without so much as making the figure flinch.
Once the spells stopped, Flitwick pulled out his wand and stepped out from the armor's embrace, at which point it faded away. "While this isn't normally covered until you learn the spells, the standard Shield Charm will either absorb or deflect incoming spells, rather than dispersing them as the Dematio does. In the case of the former, the Shield actively drains magic from the castor to maintain. In the case of the latter, the Shield can be damaged, and collateral damage can also result. Even Shield spells specialized for a specific type of magic only perform so well...but when cast defensively, the Dematio out performs them all for so long as the caster's Determination is stronger than their attacker's...and can plainly be cast by a First Year without causing an undue drain on their magical stores. It is for this reason I feel it should be taught to every student, as soon as possible.
"Admittedly, it is still a complex spell," he continued thoughtfully, "and not part of the standard curriculum, much like the Patronus. As such, failure to master this spell will not count against anyone of any year. It is merely being taught because of how useful it plainly can be." He then proceeded to explain and write out the theory he'd deduced behind the spell, as well as the difference between it and other spells he'd shown to add focus, before instructing everyone to attempt to cast, making their focus being on conjuring their Dematio as a protector.
Harry was, unsurprisingly, the first to manage it. While the points he received for it were minimal, that was understandable as he'd already demonstrated mastery of the spell when he'd unwittingly created it, and had already received points and awards in that regard. However, the conversation that began going on around him caused his good mood to start to fail.
"It's Deh-mah-shi-oh, not Deh-mah-tee-oh," Hermione lectured imperiously. "And you have to thrust through the center!"
"That's a 'tee' up there on the board, not an 'ess-aich'," Ron countered in irritation.
"The Latin suffix '-tion' is pronounced 'ess-aich', like in Determination!" Hermione countered back smugly. "The source of the spell."
"Well if you're so smart, why don't you do it?" Ron demanded angrily.
Lifting her nose slightly, Hermione pulled out her wand. Standing up, she performed the motions flawlessly. "Dematio Invocus!" she called out firmly.
There was an airburst, and crimson mist erupted from her wand tip before taking shape before her...in the shape of an elephant.
"Well done, Miss Granger!" Professor Flitwick crowed. "And 20 points for Gryffindor!"
Hermione looked exceptionally pleased with herself. However, Ron muttered something Harry didn't quite hear, and Hermione's pleased expression faded. As the class ended and Flitwick instructed them all to head out, Hermione's Dematio seemed to fold in on itself before collapsing into crimson dust that promptly blew away despite the absence of wind.