Stable mutagen sting

[The Droid]

You would be able to transform your victim into anyone of your choosing (that you absorbed) not just a copy of your current form.

Actually, I'd also like to see changelings get the power to drink/absorb any nonflammable reagent and sting people with it. Bonus if they can also do hobo chemistry inside their bodies, including temperature control and chemical analysis (so you'll know before hand that your stinger is carrying bath salts or that amanita thing)

I realize you said nonflammable reagents but I still think some amazing things could happen with this given that fire is a changeling's one great weakness.