...yeah. I really don't know how to prevent it from disappearing on contact with a Smasher.
I know that the code that causes it to terminate on contact with a wall is in a Subroutine in FitSamus.pac (1A7F4, to be precise), but that doesn't seem to affect collisions with Smashers. Even then, I don't think it will actually pass through the wall. It just won't vanish on contact.
You'll need someone else's help with this one.
Oh, and, regarding the Diffusion Missile. The ID of a Special Collision is the second half of the Bone/ID parameter. If it's set to 0, that just means that the ID is 0. It still exists. You may have already realize that, but I figured it couldn't hurt to throw it out there.
ty i actually figured out how to make the attack not collide with walls in the special collision data its self. theres a bit that says whether it can hit a wall or a player with its collision. i can just make it not hit walls. players are a bit harder tho, because it needs to be able to hit just pass thru them. considering the hitbox moves maybe i can make the hitbox last longer so it passes thru them, not sure if that will work tho. second to last parameter in the special collision box if i remember right?