A bag of goop?

Maybe it has some explanation from "Naseni" about what was done to you!

opening it up, you find an envelope and a sealed back of some kind of clear goop.

Okay...

Opening the envelope, you read:

"Please say 'Hello' to Sasha, all the raw plasma on the planet, as far as we know. The best way to master your new abilities is to practice with something that's easy to manipulate. Open the bag, give her a form (even a rock or lamp will do for a start), and have fun. But DON'T open the bag until you're ready."

Since you're new to this, you decide to take the note's advice and open the bag, but...