How do I format this?

I have a basic outline for what I want this to do and got it working with command blocks (image).
It's basically saying this:
When I shoot a spectral arrow, mount me on it.
When it lands, kill it.
When it's killed, give it back to me.
I know it should (probably) go in the tick.mcfunction file. I just need to know how to format it.
In the future, I might try to make it compatible with any player, but that's waaay out of my expertise right now.