There is sin, if you think, you are a good one but want to change yourself into someone who has same wings as your reasons for some exaggerated revenge. See, what if there are only last two good people thinking this same thing at same time. If one change into something, one will compelled to or even if not then there is forever to blame for one's goodness. So, Before metamorphosing yourself into something, look for the last good one. Otherwise you will do sin. A sin that can't be wash into Nectar of Kumbha as you are the last hope of goodness. Atleast for me!