"If a Dragon/Ice-type Pokémon (such as Kyurem) is affected by Forest's Curse, it becomes weak to 10 types, the most of any possible type combination outside of Inverse Battles."
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https://bulbapedia.bulbagarden.net/wiki/Forest%27s_Curse_(move)#Trivia
Before you told this, I already had read it when I was searching for the answer to Blaziken's question LOL