Dark souls vs bastards that use ?weapon name? and "infinite health"

For those who read this, I have been playing dark souls for xbox 360 since it went on sale and I faced against any type of situation, but today I have something curious; I will tell you in detail: I was in the dark forest, specifically in the albina zone and had finished with all the npc's, when I realized that there were 2 invaders, I was wearing the black knight build with the ultra greatsword and shield and had level 214, it was new game ++ so it's easy for you to be invaded, when I give it to you I notice that your life does not go down and the partner gives me from the back and I have a pixel of life, I roll backwards and I take a divine blessing and I run to the cliff that gives to the dark basin, and I remember at that moment that I had not killed the hydra, then I run and I like a zeta of elizabeth and I start to kill the golems and the hydra, but an arrow of gough hits me full, then I realize that I am attacking the 2 imbeciles bastards while I kill the hydra, when I get rid of it the "infinite" life although I know it is not infinite, it is directed towards me and I dodge and kick and fall down the cliff where the hydra was and I notice that he loses 64450 of life, but the partner gives me a backstab and I have a pixel of life, I roll back and use divine blessing and the zeta, he uses the zeta and he attacks me, there was a lot of lag and I swear, my internet is not bad, and it had not happened to me before, but I was behind it, and when I say back it is literal, and it makes me backstab and it takes me off the map and I fall into the void, and I honestly do not know what to think about it, i counted the hours of game that I have and in total are 4578: 16: 24 hrs and in my life it had happened to me that a sword in xbox 360 did that and honestly it seems to me of very bad taste, I do not use the zetas and the blessings in the fights but this was a disappointment and I could not see the ID of the player, I hope he dies at Christmas in front of his mom screaming of despair for not being able to do anything, because that kind of people should be strung with a stick for the year , I say all this because it does not make sense to play pvp in dark souls if these things happen, or to take care of yourself try to beat them by throwing them from a precipice, because that's not playing, that's trying to survive against someone who has no idea what playing pvp means in dark souls. Greetings and forgiveness for extending this.