At the beginning of act 3, after the party helped Emperor fight off the Githyanki royal guards, he will to convince you to change. And even you refuse, he still hands you a tadpole. So you always have a tadpole in hand. Not sure what happen if you throw it away or destroy it (possible??). I kept it in camp stash. And if I let Orpheus change, the animation always show Tav handed something to Orpheus. Assuming it is the tadpole, as the animation only show hand/arm movment.
I don't think this is the same tadpole, this is the one that expands the powers. You can destroy it unless you have used too many.
Orpheus doesn't always use the tadpole for changing. I have tried both paths and his dialogue is different depending whether you have obtained the final tadpole from the emperor or not. There is even a dialogue option for when you obtain the final tadpole and drop it (this one you cannot destroy). I guess this is to prevent a situation where you can ask him to turn without the tadpole, than pick up the one you dropped and turn yourself.
This is also how you get Orpheus to accept Gale as a solution. He is not going to trust Gale unless you get the tadpole from the emperor, and then change your mind. If you dismiss the emperor instantly, Orpheus will not trust Gale. From a roleplaying point of view it makes no sense, that he only trusts someone who considered eating him, but not the one who refused his enemy. It is because of the mechanics if turning, so that if you change your mind about Gale, you can still turn mid battle if required.
