Transmigrators' Guild

Looking for a Novel: A Transmigrator Takes Over the Childhood Friend's Body, and His Childhood Sweetheart Defeats Them

I can’t remember which platform it was on. As far as I recall, the heroine and her childhood friend were very close. After he left for war, a transmigrator took over his body. When he returned, he brought a transmigrated woman with him. The heroine didn’t believe he would do something like that, but in the end she discovered that her childhood friend had been transmigrated into.