Can assist or metronome be used for exclusive moves?

Question

I was going through YouTube, and while I was doing that I found an odd video of Wailord using Darkest Lariat. It's highly unlikely for that to be possible, but it did get me thinking. Let's get a more likely Pokemon to use other moves, like Skitty or Purrloin. Both learn Assist.

Let's say you get into a random encounter, and only have a Purrloin and an Incineroar. You make your Incineroar forget moves until it only has Darkest Lariat, and Purrloin down to Assist. If Purrloin used Assist, could it turn into Darkest Lariat? How about Metronome? Is it limited to specific Pokemon? If it does work, would Z-Assist Darkest Lariat be Incineroar's special move or just dark z-move.

Comments

I vaguely remember another question being answered with regard to Metronome and Signature Moves.  Metronome can still pick Signature Moves, but because the Metronome user is not the "owner" of the Signature Move (IE V-Create, Relic Song, etc), the move will fail.

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Nah, I remember back in ORAS there was an Assist strat for multi-battles called Voidcats. One person brings a Liepard with Assist, a Smeargle that knows only Dark Void and a third Pokémon that knows moves that Assist can't select. It was fun to use because of Liepard's Prankster ability. Thing is, Dark Void is Darkrai's signature move. Unless they changed the way Assist works in Sun/Moon, I'm pretty sure it can still use signature moves.

(Well, now it can't use Dark Void because only Darkrai can use Dark Void but my point still stands.)

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Once my Munchlax used Menotrome and landed on Revalation Dance. But that's not into topic.

Answer 1

Metronome (without using normalium z) can call any move that isn't a z-move and isn't on the list in the source. This means it can't call the following signature moves, but can call all other ones: chatter, freeze shock, ice burn, relic song, secret sword, sketch, techno blast, v-create
source
These are the signature moves that assist can't call: chatter, king's shield, mat block, sketch, spiky shield
source
Z-assist only calls the type z-move, not the signature z-move.
source

Comments

Yup, he's right. Metronome can copy any move except the ones he listed. I've seen my Togekiss copy Darkest Lariat (which was funny to see), Blast Burn, Dark Void (though it failed), Sunsteel Strike, and Core Enforcer.