Because Shinji didn't know where Heartless' Command Seals might appear on his body, he decided to make a set of equipment: a wristband for each arm, ready to explode whichever arm the seals appeared on. He also prepared a belt, just in case the Command Seals appeared elsewhere, ensuring that he could blow Heartless apart completely.
Each piece of the three-part set was imbued with the concept of Indra's Thunder, greatly amplifying lightning-based magecraft. Heartless, without any suspicion, wore them as instructed by Waver.
With this setup in place, Shinji could afford to take risks. He even secretly communicated with Lorelei and Waver, asking them not to press their attacks too hard, all to create an opportunity to blow off Heartless' left hand. After all, if Shinji were the only one acting recklessly, how could the others, who were all smart people, possibly go along with it? Just to reiterate, everyone here is intelligent—there are no fools!
The goal of this elaborate plan was, of course, to seize the Command Seals.
"Drink the contents of the cup, and your sins will be forgiven. This is the blood I shed for all, the blood of the contract."
As Shinji chanted in a low voice, the Command Seals on the severed hand were stripped away, along with the master-servant contract between the shadow servant and Heartless. Without the contract, there was no anchor, no source of mana, and the heavily injured shadow servant's body quickly began to fade, on the verge of disappearing.
"This is the end; I have lost."
Despite this, the shadow servant's face, full of heroic determination, remained calm. She had already accepted this outcome, embracing the fate of a warrior.
"Defeat is defeat, but this might not be the end."
Shinji had gone to great lengths, setting everything up in advance and even personally taking action. How could he just let her go so easily? Holding the stripped Command Seals in one hand, he tossed aside Heartless' severed arm and beckoned to Waver with a smile on his face.
"You mentioned earlier that you avenged yourself against another Iskandar, but that's not entirely accurate. Since I was the one who acted, it doesn't strictly count as your revenge. However, now's your chance. Make her your Servant, let her become dependent on you."
"Ah—!"
The two people most involved in this decision cried out simultaneously.
Waver's eyes widened, and the black-framed glasses on his nose nearly fell off, while the shadow servant protested vehemently.
"No, absolutely not! I'd rather disappear than have him as my Master."
She began to struggle violently, trying to burn through the remaining mana in her body in this desperate effort.
Shinji looked down from above at the shadow warrior, who had fallen into the dust, his gaze full of amusement.
"Don't waste your energy. If you want to blame someone, blame your Master—no, your former Master. His excessive mana supply is enough to keep you around for a few more hours."
The survival time of a Servant without an anchor is proportional to their skills and the mana remaining in their body. Heartless' full mana supply, intended to aid in his escape, had ironically become the biggest obstacle to the shadow servant's disappearance.
"Besides, you don't have a choice now. You've been through countless battles, so you should know what happens to captives who fall into the enemy's hands."
"You—!"
The shadow servant paused her movements.
"—Even so, I will never submit to that man. I will kill him, I swear I will!"
"That's not up to you. The Command Seals exist precisely to prevent such situations."
Shinji waved the red marks he held in his hand.
"Waver could use one Command Seal to order you not to commit suicide and another to forbid you from harming him or anyone close to him in any way. Just two Command Seals are enough. If your former Master had used up one more, it might have been a bit troublesome."
"You!!!"
Forcing a Servant to obey by using Command Seals is the greatest insult to a Servant, especially to a proud and self-respecting warrior. The shadow servant glared at Shinji with eyes that nearly shot flames.
Do you think this is bad? There's even worse you haven't seen yet.
Do you believe I might lend a couple of Command Seals to Waver? Or do you think I'll make a contract with you first, then use a Command Seal to order you to wash up and warm my bed?
Keep in mind, this transmigrator is a seasoned otaku, well-versed in all kinds of harem anime, eroge, and galgames. Dealing with an ancient person like you, who's all about war and hasn't even dated, would be a piece of cake.
Cough cough, of course, all of this is just Shinji's imagination, venting his frustration in his mind. In reality, he would never actually do such things. If he were that kind of person, how could he have refrained from making a move on the many girls around him? How could he have consistently tried to push her towards Waver, rather than keeping her as his plaything?
Sigh, sometimes having too much integrity and a strong moral compass isn't a good thing, though, in the current chaos, it's more of an advantage than a disadvantage.
While Shinji's mind was filled with all sorts of inappropriate thoughts, the words that came out of his mouth were much softer.
"I know I'm being somewhat excessive, but this isn't all bad. The Fifth Holy Grail War is about to begin, and Waver is likely going to participate. And who will he summon? It'll be that Conqueror King. Don't you want to vent your anger on him face-to-face?"
This time it was the shadow servant's turn to widen her eyes. How could she not want that?
In the few days since she was summoned, she had dreamt numerous times of standing at the edge of the illusory "Endless Sea"—
"King!"
"My King!"
She called out!
She roared!
She questioned!
She raged!
She reprimanded!
"Why did you pursue such a place? Why didn't you abandon it? Knowing it was just a dream, why couldn't you let it go?"
As the shadow of the King, she understood him better than anyone and was more loyal and devoted to that great King than anyone. And because of that, after the downfall, she was so angry, resentful, and confused that she refused to respond to his summons, refused to join that unparalleled army spanning Eurasia and Africa, refused to stand by the King's side—where she truly belonged, closer than anyone else.
"Answer me, Iskandar!"
Until she could understand this, until she could resolve this inner turmoil, she would remain in this state. And only the Conqueror King himself could provide that opportunity.
Seeing the conflicted expression on the shadow servant's face, Shinji continued to speak: "And don't judge Waver too harshly before you get to know him. He's come a long way from being an ordinary boy, stumbling along to become someone many magi look up to, all because of the Conqueror King's charge and command. Ten years—how many ten years does one have in life? To remain steadfast even after the King is gone, isn't that far better than those who start fighting among themselves the moment their King dies?"
The last sentence tipped the scales decisively. She was no longer the same person she had been in life. Knowing about the Wars of the Diadochi, knowing about the fall of the empire, made this kind of steadfastness all the more significant.
"You've convinced me. Though I still don't fully accept him, he is indeed much better than those fools. But let me say this upfront: if he disappoints me, I won't be polite."
"That's between you two."
Shinji looked at the shadow servant's face, which bore a striking resemblance to the young Iskandar, and then at Waver, who exuded a mature and intellectual charm. Satisfied, Shinji smiled.