But testing it properly was not so simple. If they wanted to meet Tver's standards, they would at least have to reach the point where the imp could cast the way they themselves did in normal combat.
For students like them, even the latter was hard to maintain for long.
So Tver decided to start by teaching them how to make their imps cast the Shield Charm.
"Next, I'm going to keep casting spells at you, and you are only allowed to use your imps to cast the Shield Charm in defense!"
"But don't worry, my spells won't knock you unconscious."
"I'd honestly rather you just stunned me," George said at once, voicing what everyone was thinking.
"Hm?"
"I mean..." George immediately straightened up, suddenly looking extremely serious.
"We still can't even control the imp to output magic properly, and you want us to start with a high-difficulty spell like the Shield Charm right away? The imp doesn't even have a wand. Isn't that a bit too much for us?"
"Then practice more."
Tver raised his wand with ill intent in his eyes, but instead of aiming at the students, he pointed it at the imp, drawing surprised looks from everyone.
"Watch carefully. Though honestly, you do not have to watch that carefully, because I'll be demonstrating this many, many times after this."
As soon as he finished speaking, the imp's smiling face flew up above Tver's head. Wearing a meaningful grin, it quickly swept its gaze across the room, making sure everyone was watching.
Then it raised one tiny hand with no fingers, and a bright red streak of light shot straight at George without warning.
"Protego!"
At the critical moment, George's combat instincts kicked in. After all the battle training he had been through, he reflexively threw up his wand and cast a Shield Charm on himself.
Bang!
The Shield Charm seemed to melt away. The red light did not slow in the slightest. It punched straight through the invisible barrier and struck George cleanly, sending him flying.
Tver lowered his wand, not looking very satisfied.
This was a result Godric had developed through his research on the Sword of Gryffindor, a way to make magic pierce certain protective spells.
But the flaw was obvious too. Its power was too weak.
He had clearly used a powerful Knockback Jinx, yet after burning through the Shield Charm, it had only managed to flip George over.
"This is a kind of magic that can pierce the Shield Charm. It's also a warning to you. There are spells in the wizarding world that the Shield Charm simply cannot block, so you must be careful. Very careful."
"But, Professor," George said, climbing back up with help from Cedric and Fred while rubbing his aching backside, "even if we do get the imp to cast the Shield Charm, it still won't stop that!"
"Oh, sorry. The spell that hit you is different from the one I'm about to use on everyone else. You're just special."
Tver answered him with a broad smile that did not contain the slightest hint of apology.
"Urgh..." George whimpered and instantly stopped making random remarks.
But the other students all felt a chill at the same time. They had immediately realized the professor was playing his combat games again.
Back when he had first arrived at Hogwarts to teach, the first thing he had taught them was combat.
Not how to fight, but how to get beaten while hanging in the air.
Old memories surged back, and the Hogwarts students' expressions turned deadly serious. They focused intently on controlling their imps, squeezing every bit of practice they could out of the time.
The Durmstrang students reacted a beat later, but because they were relatively more familiar with Tver, that smiling face that did not quite reach his eyes instantly brought back the terror of being dominated.
The Beauxbatons students, meanwhile, were still baffled. They looked at the others in total confusion, vaguely feeling that they were always out of place simply because they were too good-looking.
"The professor's really nice. He answers our questions and hardly ever loses his temper with us..."
Bang!
A red flash slammed Fleur to the ground mid-sentence. She landed hard on her backside, so painfully that tears nearly sprang to her eyes.
Davies, standing nearby, let out a cold laugh and made no move whatsoever to help her up.
"The professor really doesn't lose his temper with us much, because he doesn't need to. He can deal with all of us without it!"
He was not the same shameless bootlicker he used to be. He was going to be an upright, dignified man from now on. No one would ever make him bow and scrape again. No one. Never agai-
Bang!
Magic fired by Tver's imp pierced straight through the thin layer of Shield Charm Davies had just managed to put up and knocked him flat on the ground.
"Student Davies is doing quite well. You can already make the imp release a layer of magic, but keep working at it."
Tver looked curiously at Davies, who was sprawled on the floor with a complicated expression of grief, pride, and indignation tangled together on his face.
"What's wrong? Did I hit somewhere I shouldn't have?"
"No." Davies hesitated, then shook his head. "It's just that the professor's praise moved me a little."
"Then keep it up."
"Yes, sir!" he declared energetically.
If it was the professor, then maybe it was acceptable!
But Davies's rapid progress was only because he had been holding in a breath of frustration and had managed to overperform.
In truth, making an imp cast magic was the hardest part of the day's activity.
First, even though it was still their own soul casting the spell, the extra step of routing it through the imp meant that many of them could not transmit the full intent of spellcasting properly.
Second, the imp had no wand and could not speak an incantation. For them, this felt somewhat like nonverbal casting, except even harder.
So by the time the activity ended and evening came, only a very few of the strongest students had managed to make their imps cast even a thin, fragile Shield Charm.
"Don't be discouraged. You can still practice this after you go back. It'll help improve your understanding of silent and wandless magic!"
"Practice is over. Recalling the imp is simple too. Just control it to revert to its original soul form, then stuff it back into your head."
"Like this."
With a wave of Tver's wand, his imp instantly turned back into a nimble wisp of soul and slipped lightly through his temple back into his body.
"But Tve... Professor," Viktor asked before leaving, voicing the question that mattered most to him, "are we only practicing the Shield Charm? Can imps use other spells too, especially offensive magic like yours?"
The moment he heard that imps could cast spells, he had immediately realized how much potential this magic had in combat.
In the wizarding world, a thing like this imp was obviously unique.
If he had an imp above his head in battle, even one that only automatically cast the Shield Charm for him, it would free up his main body and let him focus more completely on his own spellcasting.
And as someone who had studied combat deeply, he was not satisfied with just the Shield Charm. What he wanted was for the imp to launch unexpected attacks at an opponent, or even better, to have more than one imp and drown the opponent in magic.
Tver was very pleased by Viktor's cooperation, and a smile naturally appeared on his face.
"That depends on how quickly you learn. If you have the spare capacity, I won't forbid you from expanding this magic in any way."
"I might even arrange an imp duel tournament for you all."