Can anyone tell me what this is saying?

[GhostriderKami]

So basically im trying to find out the pointer of health. It is multileveled pointers.

It goes like this: mov [rdi+rax*8],r9d
So i thought, okay cool it moves the value from R9 to RDI+RAX or something. Only problem is RAX is just some 0, and RDI is the current adress. So my question is what the *8 means.
If someone could help me, that would be nice.

[GhostriderKami]

Also what the d means of r9d, by any chance.

[Dread_Pony_Roberts]

the *8 multiplies rax by 8. Since RAX=0, you are multiplying 8 by 0.
Just use RDI.

r9 is normally an 8 byte register (QWORD), but r9d uses only the first 4 bytes (DWORD)