LEGO Ninjago: Dragons Rising

They Call it Doom (1x15)

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All three Ninja teams near the end of their hunt for the Dragon Cores. Kai and Wyldfyre scramble for the purple Core against Dorama and the Lava-tides. Lloyd and Arin enter a trial for the pink Core with unexpected consequences. In the Valley of Lost things, Nya and Sora search for the purple Core but instead find an old friend.