No matter what Seto Kaiba you're dealing with, his life's dream is to bring joy to children. He has varying layers of armor from various traumas, more in the manga than the anime I'd say, but the core of him is the same in both.
That is, more than anything, the part of him that I celebrate in my work.
.
Masahiko had had no intention of spending the night at the Kaiba Estate; he'd fully meant to, eventually, request a ride back to his hotel room. However, when his counterpart offered to play some games with him in the cave, Masahiko hadn't seen any reason to refuse. So it was that he and Mokuba both fell asleep in the recreation room on the second floor; he'd been moved, by Roland Ackerman at Seto's instruction, to a spare bedroom on the third floor so that he wouldn't sleep on the floor all night; no doubt Seto had thought long and hard about hefting the boy up himself, but eventually decided he needed the use of both arms before trying something quite that delicate.
When Masahiko woke in the middle of the night, in a foreign room, he felt a shudder of superstitious terror; then he remembered that he'd been playing videogames and calmed down; but he still wondered, though now with curiosity rather than fear, where he'd been taken. In this sleepy haze, he didn't notice anyone else in the room at first.
The boy's natural sense of caution—which had been called, on more than one occasion, pure paranoia—didn't help him; it wasn't until it was far too late that Masahiko realized he wasn't alone.
The black figure fell upon him and clamped a hand over his mouth in the same movement. Masahiko yelped as he stared into a sneering face he couldn't recognize. "Time to reunite with your brother, little prince," the figure whispered in a husky voice made thick with . . . something. Alcohol? Some other drug? Power? Lust?
Masahiko kicked, pulled, thrashed around, all while he strained to make himself heard over the shadow's hand; the best he could manage was a pathetic little mewling sound that he never would have recognized as his own voice. Nothing was enough, nothing he could conjure could dislodge a fully-grown man laced over with muscle. The boy's eyes were clamped shut in denial, horror, grief, and every other emotion known to humanity; tears sprang from the corners as he strained with everything he had left to slow his breathing.
He was hyperventilating.
His brother's voice, back in the depths of his memory, urged him to scream, bite, kick, fight. He thought about everything his Niisama had ever taught him about what to do when backed into a corner, how it didn't matter what you did so long as you lived.
Quite possibly the last piece of honest advice he'd ever given his brother.
But in this moment, trapped as he was in a foreign world, on a foreign bed, huddled under a foreign threat, all Masahiko could do was cry. The boy known to his (few) friends as Kaiba-sama; the boy known to his employees as Mokuba-sama; the crown prince of Domino City sobbed quietly as he waited for death.
He felt a blade against his neck and kicked out a leg from sheer instinctive terror.
Something—he would find out later that it was a small vase, holding a bouquet of silk flowers meant to offset the wallpaper—tumbled off its table and crashed onto the floor. The shadow flinched just enough, moved his hand just enough, that Masahiko wrenched his head to one side.
He had one chance.
He had one moment.
He screamed.
"HELP!"
The shadow's hand was on him again, immediately, cutting off his desperate wail, and Masahiko felt sharp steel against his neck again. "Who do you think is coming for you?!" the shadow hissed between yellowed teeth. "Interloper! Trespasser! No one will save you. No one will put themselves in danger for you. Even your own brother doesn't love you enough to lift a finger for you. You know the truth. You know your worth."
Masahiko focused his eyes on the shadow's face.
He decided, in that moment, that if he was going to die . . . then his killer was going to have to look at him.
Just as the knife was starting to bite, just as the first trickle of blood met the midnight air, the door crashed open. It flung inward and careened against the wall so hard that one of its hinges dislodged. Standing there, bigger than life, silhouetted against the lights in the hall behind him, was the master of the manor.
The shadow barely had time to realize the danger before he was wrenched off the bed and thrown backward with all the force of a raging bull. The shadow crashed against the sharp threshold of the open doorway and let out a staggered grunt as the air was pushed out of his lungs.
Seto Kaiba announced himself in between his target and his charge. His right arm was still held tight to his side in its sling, but Masahiko didn't think he'd ever seen such a mythical figure in all his life. The man was taller than God.
"You picked the wrong night to be stupid," Seto said, almost gently.
The shadow shook his head and growled, low and guttural. "You think you're special, you think you matter, but in the end you're nothing but an obstac—"
Seto whirled and sent the heel of one foot into the shadow's throat, choking off the rest of his challenge. Looking so transcendently disgusted that Masahiko was forcefully reminded of his own brother for the first time, the eldest Kaiba stared down at the shadow as he crumpled to the floor.
"I didn't give you permission to speak."
Masahiko pushed himself against the wall, scrambling to a sitting position, as footfalls thundered up the stairs. A moment later, a sea of black uniforms obscured his view of the man who'd tried to kill him.
"Sweep the building," Seto snapped. "If there's a rat where one shouldn't be, I want to know about it. Call Team Zephyr. I don't care what time it is when you finish. I want a full report. Aunt Shelly can wait; get on with it. Now."
No questions. No objections. They were gone almost as quickly as they'd arrived.
Seto turned, slowly, to face Masahiko.
The boy strained to slow his galloping heart.
"You . . . you heard me."
Seto stepped inside the room, pulled a chair from the nearby desk, and sat down. "Yes," he said. "I heard you." He gestured out into the hall with his left arm. "I've been checking the cameras more often, ever since this whole nonsense started. One could get away with calling me obsessed." He sighed. "I saw that one a few times before I realized he wasn't a trick of the light. I wasn't sure what his goal was, but once I saw him on this floor, it didn't matter."
"It . . . it didn't . . . ?"
Seto locked eyes with Masahiko. "No one hurts a child under my roof."
A stern, stifling silence followed this declaration, in which Seto looked as young as he ever had; in this moment, on putting words to this commandment which guided his life's mission, he had never seemed more idealistic. And yet, there was a conviction in him, an authenticity, which couldn't be ignored. There was no way to look into his eyes, to listen to him say those words, and not trust him.
Part of Masahiko wanted to say that Seto couldn't know that; he couldn't promise that. But that part of Masahiko was small, and couldn't find its voice in that moment. That part of him withered, in fact, and died. Right along with the last dregs of mistrust for this stranger who had never felt more familiar. This stranger who was more like the brother he remembered than his own brother had been in years.
Before he knew what he was doing, before he could think about how much of a mistake it was and that there wasn't a way he would ever get away with it, Masahiko threw himself at the man who looked like his guardian, and the tears finally came in fierce, racking sobs. As he realized what he was doing, he waited to be rebuffed.
He waited for Seto to push him away at arm's length.
To offer an embarrassed little chuckle as he said something like Hold on, kid, cool your jets.
But that didn't happen.
Seto's left arm wrapped around Masahiko's shoulders and pulled him close, as he rested his chin on the boy's head. "It's all right," he whispered, as Masahiko cried against his ribs. "You're safe here. Let it out. He can throw everything he has at you. He can throw whatever tantrum he wants. Nothing will hurt you again. Not in this house."
Masahiko believed him.
