[quote=@Blizz]
How arena rp works,for example(I kill you,No,I killed you) what decides who kills who(I'm asking because fights in rp seems strange to me)
[/quote]

Physics decide that. If the opponent launches a potentially lethal strike, and you have no means of avoiding it, then you're dead. It's a bit trickier with things like blood loss, but as long as your opponent describes well what kind of damage they receive, you shouldn't have problems with the long-term effects of wounds and trauma either.