In the next Larp, we will be talking about inserting a void* __vftable at 0x0 of every struct, then dynamically populating the address pointed to with function pointers, all of which require rcx to hold a pointer to the structure instance.
you can implement inheritance in C with one simple rule make the parent struct the first member
C guarantees that a pointer to a struct has the same address as its first member so casting between them works