I know I always say the same thing but the whole point of having someone reincarnated into a non-humanoid (like a virus, a sword, a spirit, a vending machine, a wand, a bath or whatever) is to experience another way to deal with things. Having them aquire humanoid bodies right away totally defeats the point and becomes a simple gimmick to explain their powers instead of being a defining feature.
If you can't write your story properly without giving a human body after a couple chapters to your protagonist, then don't write it.