You're thinking of will and consciousness being human will and consciousness. That's the mistake. Read Schopenhauer. Nietzsche is borrowing heavily from him and assumes his readers would have been familiar given the era and the culture. Schopenhauer's concept of consciousness / will is very pegan / pan-consciousness.

I think the key you're missing is the concept of identity. It has to go.

Think of the question, are you identical to you? What about you today vs you yesterday? Identical? (And I could play all of this college games here).

Identity is a bad tool in many areas. If you have phillips screw and someone hands you a hex wrench, do you try to figure out why the hex wrench doesn't fit, do you philosophize about how the world would be different if the screw had a different head, or do you say.... this hex wrench is a poor tool, put it down, and grab a phillips screwdriver? Identity is a bad tool. It just doesn't fit. If two things are identical, they are one thing, not two (identity of indicernables). Ergo, identity is something we never really experience, and never seriously apply except in theoretics.

It's easier to think of yourself as recurring. You're you, just like summer is summer. Identity isn't required, and you can will your recurrence. Go work out. Recur bigger. Recurrence is the rule. Identity has nothing to do with it. (The problem is the verb "is," it doesn't account for becoming. This misleads many English speakers).

Also, beware of thinking nietzsche was just doing cute, academic thought experiments. It's how people lead others to dismiss the very heavy concepts he was dealing with, including the nature of being itself.