I wanted to make this chapter for all those who haven't played Sekiro- Shadows Die Twice. So this chapter will explain all the important stuff from the Game which I have stated in the first few chapters. I don't want for readers to feel confused on what certain things are, and what they do.
1) Second Mortal Blade: It is also called Black Mortal Blade, a powerful weapon that has the capability kill immortal beings.
It is also called "The Gate to the Underworld" as it has the capability to revive the dead directly from the afterlife, however, at the expense of the life-force of the user. The more powerful the summoned being, the more life-draining it's effects are upon the user. One can even outright die if the summoned is stronger than the user, or the user runs out of life-force/ vitality, thus one must be careful while using this ability.
Due to it being a Mortal Blade that can kill even immortals, any injury caused by it is extremely hard to recover from, or even unrecoverable, depending on how severe the injury is.
2) Healing Gourd: Also called the waters to Rejuvenation, it can recover the vitality and stamina of the person who drinks it. It can be used a maximum of 10 times, and will only completely refill upon the owner rests or each use will be replenished 3 days after every use on its own.
3) Sekiro: The main character of the Game, who is a Shinobi who goes on a quest to save his Master, Karo, and sever immortality. To achieve this goal, he had to kill even Isshin the Sword Saint.
4) Ashina: The game is set in this Kingdom, of which, Isshin was the king after he rebelled against the cruel rulers and won. The story of the game revolves around severing immortality and the destructing of this Kingdom by invaders.
5) Gyoubu Oniwa Masataka: He is the 1st boss in the game Sekiro, and is basically just a learning boss for players to learn how to play the game, and the basics of its mechanics. He is a giant man, and rides an equally giant horse. He used to be a bandit, but was defeated by Isshin, who was impressed with him and made him the protector of the gates of Ashina.
6) Reflection of Strength: It is a sort of Game mechanic where the player could fight any of the bosses he had previously fought and won. It is done to practice beating the bosses better, experiment with new weapons and play styles, essentially, do whatever you want in a boss fight, all without the threat of any losses, as this just a memory. Any losses or wins or use of any items inside this mode does not affect anything in the real world. Players usually use this mode to abuse bosses out of Sadism.
7) Mikiri Counter (GOAT Skill): Ask any person who's played Sekiro properly, and they will all tell you that the most important and cool skill in the game is this. The Mikiri counter. What happens here is when the opponent uses a stab attack with any weapon, you stamp onto the weapon, forcing it into the ground and thus causing the opponent to go off-balance, allowing for essentially guaranteed hits. It also has really cool visual and sound effects, and makes you feel like a Giga Chad whenever you use it.
That's all the important things so far. It may feel like an info dump, but please bear with it. The readers need to understand what each of these do, or they will feel lost during the important moments.