Toaru Majutsu no Index - Volume 10, Epilogue: The Awaiting People after the Conclusion. Those_Who_Hold_Out_a_Hand.

The year 1847

The Empress who dies in torture, An Rushuang is her name. After she wakes up, she finds herself has time-travelled to when she was twelve years old, but she would turn into Major General’s white horse at night. He is a general who orders about the winds and clouds on the battlefield, and she is a little girl lives in her boudoir seclusively.
She endeavors to change her fate, and he spared no effort to win every battle. They meet each other every day, well, it’s night to be accurate. Is that a dream or not? She pleads to marry the seignior to win peace for her family, only to find he is the one she is going to marry.
“Growing old with you under the same roof is my long-cherished wish”, thought them both.

- Description from Novelupdates

This is the story of Ryo, who was reincarnated in the world of swords and magic.It is a story of the royal road to survive using the magic of water attribute.What is magic? What is swordsmanship?How does it relate to the laws of physics that we know?Or what is politics? What is a nation?Why are there many 『kingdoms』 in reincarnation stories? Will republics not work?Can it be written …?Since it is a water-based magician, so it shall start with 『Hydrogen bond』!

The summer night passed through and passed through the world of Marvel movies!
“But, it appears directly on the battlefield of the bullets, what is the start?”
“And why is my golden finger a decomposition machine in DNF?”
[Decomposition equipment is successful! 】
[Advanced sniper shooting experience *100]
[Decomposition equipment is successful! 】
[Advanced Fighting Techniques Experience *100]
[Decomposition equipment is successful! 】
[A dazzling battle of souls, can enhance the strength of body attributes! 】
“Can it be better than God?”
[That is just the starting point! 】
“then continue to break down!”
[Decomposition equipment is successful! 】
[Cannot look directly at the exercise *100]
“…”

- Description from Uukanshu translation