Everyone gets told that Satan/Lucifer is a sinner and the worst entity ever existed. But NO according to the Christianity itself God created angels for the only purpose of them to serve him without question, they basically have no free will as humans have(they say) or they just can't do anything against God's will. So about Lucifer wanting to become #1 in power is either a God like act since he managed to cut God's bonds of making Angels his servants, or the God that they say that does no mistakes, did something wrong with creating Lucifer! Either way it is God's failure/weakness. Everyone would want an upper place, no one wants to be second in command and that is something "natural".
Lucifer is still an angel. A fallen angel though. He is still good. He does nothing bad as God won't allow him to do so and him getting blamed for all the bad things happening is just..God made a plan for us so who to blame is he, Lucifer did not create us so we can not blame him.
As stated before Lucifer is still good (always was good) according to some books of Christianity he even apologized to Christ without asking for forgiveness!