How is the result of battle determined?

It is purely determined by your Blood Weapon stats.

How is attack stats determined?

Attack stats are determined by the combination of your Blood Weapon raw stats plus all the event bonuses.

How is defense stats determined?

Defense stats are determined by the combination of your Blood Weapon raw stats plus all the event bonuses.

What is Item Bonus?

It is an item that raises your Blood Weapon stats.

What is Luck Bonus

Luck Bonus is a bonus that will randomly raise your Blood Weapon stats during your PvP battle. 

What is Rage Bonus?

Rage Bonus is a bonus that you gain after losing against an opponent.
This bonus will raise you Blood Weapon stats.
There is no limit to this bonus. The bonus will keep accumulating until you win the battle. 

What is Accomplice Bonus?

Accomplice Bonus is a bonus that will raise your Blood Weapon stats.
The stronger your Accomplice, the more it will raise your Blood Weapon stats. 

What is Chain Bonus?

Chain Bonus is a bonus that increases every time a revenge attack is successful. The more Chain Bonus you gain, the more Blood Points you will earn.
However there is a limit to the Chain Bonus. The Chain Bonus will be capped at 20 but the number of chains will keep increasing.

What do you get for winning a battle?

You will earn Blood Points every time you win a battle.
There are also rewards for reaching certain amounts of Blood Points, so gather as much as you can! 

How does the battle logic work?

Battles use Blood Weapon stats and it's bonuses. If your total Blood Weapon attack stats, after bonuses, is larger than your opponents Blood Weapon defense stats, you will win the battle.