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Is it possible to catch all Pokemon through each corresponding gen?
Gen 1 - Mew doesn't count
Gen 2 - Impossible, because you need Gen 1 for the Fossils, the starters, the legendary birbs and Mewtwo, Celebi and Mew don't count.
Gen 3 - Possible, no Ho-oh, Lugia, Deoxys, Jirachi, Mew and Celebi needed.
That's all I know. What about Gen 4, 5, 6 and 7?