Ok, I am obviously not good at explaining my thoughts very good (Blame the Asperger's).@KS
Still not clear on what you're saying. So does Night Shade take the place of Metronome entirely until I get Metronome, or just for the rival battle? Also, I don't know why you bring up Watson since he's not a part of the challenge. And you can't actually get Metronome before Watson anyway, since you need to be able to use Rock Smash to get there.
Ok, until you get Metronome, Night Shade is in its place. Just remember that Metronome must be aquired at the first opportunity. As for the Wattson thing, you were talking about just before Flannery.
Jeeze, now I've confused myself >_>