1) Code expert 2) Ethician 3) Moral thinker 4) Morality expert 5) Philosopher 6) Writer on moral issues 1) Ethician 
An ethicist is one whose judgment on ethics and ethical codes has come to be trusted by a specific community, and (importantly) is expressed in some way that makes it possible for others to mimic or approximate that judgement. Following the advice of ethicists is one means of acquiring knowledge (see argument, argument from authority). The term ju...
• (n.) One who is versed in ethics, or has written on ethics.
Eth'i·cist noun One who is versed in ethics, or has written on ethics. 
[n] - a philosopher who specializes in ethics
ethician noun a philosopher who specializes in ethics
a person who specializes in or writes on ethics or who is devoted to ethical principles.