So... now what?

It seems very strange that the villain's sidekick doesn't know what to do next.

I'm assuming Pest Sprout didn't know the best way to kill Quest Sprout, and was waiting for Eternal to tell him what to do.

You'd think they would've practice their scheme a few hours prior before it began.

I interpreted this as "Do I really have to kill him?" or "I don't wanna kill him!"

That's also very likely!