Is there a way(continue below)

You can connect your desktop monitor to your laptop, either directly with an adapter. The laptop will use the laptop graphics but display on the desktop monitor. Depending on your laptop you can change the settings to something appropriate for the desktop monitor (like resolution and refresh rate). Not quite sure what you are asking by "use the hardware resources of desktop"?

its the other way around, he wants to use the desktop power on the laptop monitor.

Sorry, no-go. Unless you can remote desktop connect into the desktop from the laptop and run it over you network. Often the screen colour depth reduces so its not great.

Yeah, you're correct there.

Either remote-desktop or nothing. Remote desktop is pretty... not good.

I wish it were otherwise. There might be better rdp solutions out there, but its getting a bit technical at that point.

I mean, it is probably possible, but I imagine it's rather complex and requires rare parts. Just not something you can practically do.

NO...

Technically .. yes, easily no.