You win when the opponent has no more life, when you dont have chakra or dont have enough for a specific jutsu you cant use anymore jutsus that waste up chakra unless you meditate to get more chakra, when you dont have stamina or dont have enough for a specific jutsu you cant use anymore jutsus that waste up stamina unless you meditate to get more stamina.
Ok i will make an example of a fight.
Player 1 posts
----------------
Fireball Jutsu (-10 chakra, 10 damage)
HP-100
Chakra-90
Stamina-100
Player 2 posts
----------------
Replacement Jutsu(-5 chakra)
HP- 100
Chakra- 95
Stamina- 100
Player 1 posts
----------------
leaf rising wind(-20 stamina, 10 Damage)
HP-100
Chakra-90
Stamina- 80
Player 2 posts
---------------
Waterball Jutsu(-10 chakra, 10 damage)
HP-80
Chakra-85
Stamina-100
etc...
Academy student/ Genin- Can post 1 attack only per post
Chuunin/Jounin-Can post 2 attacks per post
Legendary Sanin/Kage/Kage(Legendary Sanin)-can post 3 attacks per post