The Fushan Curse is one type of mountain wild spell whose power is triggered in the instant the cursed person loses their fighting spirit or consciousness, releasing green mountain fire in all directions indiscriminately and transporting the cursed person out of the battlefield to a plant-covered area within two hundred kilometers.
However, it requires a significant disparity in magical power between the caster and the cursed; otherwise, not only will it fail to trigger, remaining in the body of the cursed for an extended period can actually be harmful.
Moreover, this kind of mountain spirit magic must rely on a connection between the two parties to be activated, so there's a drawback that during the curse's active period, they cannot "share a bed" or rashly exert their vital energy, or else the connection will be severed.
Perhaps unintentionally or perhaps deliberately, Li Yan's actions during the frigid winter and cheering for love with Wei Dan, were tracked by Lady Dan's magic.