That's still only within the mindscape. In his incarnated form he can be hurt, and has been shown being damaged by conventional means.
I was saying that in regards to the fact that Bill, when in the real world, can be interacted with, which also includes his soul, meaning Sephiroth can damage and destroy Bill's soul when in the real world. Just because Bill's spirit is (hypothetically) untouchable in the mindscape, does not mean it applies here.
Dipper and Mabel when they enter the Mindscape have extreme reality warping which is why they can do stuff they cannot do irl. Unless Sephiroth can enter Mindscape he wouldnt be able to interact with Bills Soul and Mind.
... Actually, fair enough. Bill isn't exactly a ghost and can't exist outside the mindscape unless he can make a deal. Sephiroth could maybe go to the mindscape since Sephiroth can seperate his spirit from his body, but that would be too dubious to make an arguement for. That being said, If Sephiroth could enter the mindscape, I still think he would be able to harm Bill, since I still think the NEP bill hasn't doesnt make him untargetable, and Sephiroth has been shown/stated to interact with and harm spirits.
All that being said, this NEP dissappears the moment he comes out of the mindscape and is incarnated into the real world. Once that happens, all bets are off and Bill's soul can be targeted and destroyed like any other physical being, since Ford's Quantum Destabilizer would have destroyed both Bill's body and soul had he had actual aiming skills. Bill's soul isnt separated from his body when he's in the real world, unless decides to exit his physical form.
They were able to harm him only because of them being in the mindscape state as well, as when Dipper was in the mindscape form in the real world, no one would touch or see him.
So quit with the dishonesty, thanks.
Rude and go **** yourself, but whatever. The mindscape isnt what I was focusing on anyways, its Bill's physical form i was focusing on.
Still it doesn't mean I'm wrong. Bill's NEP doesn't make him invincible and Sephiroth can harm spirits, its just that in this case Bill in his mindscape form exists on a plane Sephiroth has no method of reaching by himself.
Sephiroth does not directly target the soul with his attacks.
This is Sephiroth's spirit taking away another spirit.
This is Sephiroth's soul fighting another soul, so not directly hurting the spirit
All these factors I mentioned show that Sephiroth can target and damage the soul should he desire to, and its not limited to any particular spell/ability/attack Sephiroth has, its something he can do himself.