I was recently speaking to Joel of your support. I wanted to check on the status of this players investigation or resulting punishment. He was using Dark Souls Trainer to give himself infinite health, infinite stamina, unlimited spell casts, unable to be poisoned, unable to be bled, and unable to be cursed. He also had all of his stats maxed out and was only maybe Soul Level 20-30ish. He was fighting a buddy of mine when he invaded my world, my buddy was kicking his ***, and he instantly full healed and it showed his health had gone up to 68k.
The only way we were able to get rid of him was to double-team him towards a ledge with weapons that could stun and force him off.
I have also submitted a report with Steam/Valve and hope that you will cooperate with them so that not only does his XboxLive/GFWL account gets banned, but his Steam account as well.