Not sure of the validity, but this is taken from another forum:
Not that it's hard at all to find this info but I still rather not post a link but this is copy/paste of the "features".
Now, onto business. This eboot will make it so no enemies can harm you, with the exception of the red knight and apparently one boss. To my knowledge there are no side effects, as I'm playing through it, I'm making notes of what has changed.
Standard enemies won't hurt you
Fire won't hurt you
Dragons won't hurt you
Falling WILL hurt you
Traps WILL hurt you
Lava WILL hurt you [just found that out the hard way]
Corpse Ball WILL hurt you
Red Phantoms WILL hurt you
Black Phantoms WILL hurt you
Miranda WILL hurt you
Old Monk WILL hurt you
Old King Doran WILL hurt you [just had my ass stomped in surprise]
Fire and enemies won't damage the environment - ie wood, crates, etc
World Tendency is NOT locked. Extensive testing done.
If that wasn't enough it comes with infinite souls as well.