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This really looks like a Mon that doesn't need a prevo. The prevo will also very likely be just the small dragon, who is literally the same Pokémon, so a large part of the process will already go to waste since not much else would fit. The small dragon does not really fit trapping moves too, so there goes the LC niche. Finally, it just doesn't feel good. A small dragon that can fall asleep just fine, but at a certain level it can't wake up anymore and its dreams appear? No, that makes 0 sense.