I'm going to copy @JMcAfreak's disclaimer because it applies to me too. I'm glad user contributions are licensed with a Creative Commons license.
DISCLAIMER: I am not a legal professional. The advice provided in this answer is not exhaustive and should not be considered complete.
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I may however have slightly more expertise in copyright than the average person because I recently completed a wonderful free MOOC (massively online open course) at edX.org called HLS1x or also just CopyrightX. I mention this only as context for my following answer, but CopyrightX is taught by William W. Fisher III, professor and director of the Berkman Center for Internet and Society at Harvard Law School, and it mirrors the course that law students at HLS take (I took the same final exam that they took). I think it would be very difficult to find a more exhaustive treatment of the subject anywhere in the world without getting a JD, and this course is totally free to everyone in the world.
So with that context, I can say that almost everything @JMcAfreak wrote in his answer is something that I specifically recall having talked about in CopyrightX on edX. I agree with everything he wrote about Fan Fiction.
I also agree with most of what he wrote In General.
Here I'll depart slightly, though. My first thought is that you should clarify which country's laws you wish to abide by in terms of copyright compliance because there are significant differences. These are discussed in the CopyrightX course if you'd like to study the matter further on your own.
Assuming the US is the target country, I'll say that there really are no certainties in US copyright law. The Richard Prince appeal decision came as a huge surprise to everyone at Harvard Law School, and that decision could be interpreted to be very highly in your favor with regard to your plans. However, if you spend 12 weeks reading judicial opinions in high profile copyright cases, it is impossible to leave the experience thinking anything except that copyright law is interpreted entirely at the whim of the judge involved, and that little to nothing is predictable aside from the cost of pursuing or defending a copyright case in federal court which averages about $60,000 per day at an average duration of 18 days. Based on these two aspects, I absolutely agree with @JMcAfreak that "Copyright is a landmine you don't want to step on."
I think that even the US Register of Copyrights (Maria Pallante) would agree because two months ago, she testified before Congress that, "The law is showing the strain of its age and requires your attention. As many have noted, authors do not have effective protections, good faith businesses do not have clear roadmaps, courts do not have sufficient direction, and consumers and other private citizens are increasingly frustrated. The issues are numerous, complex, and interrelated, and they affect every part of the copyright ecosystem, including the public at large." She also said, "...if one needs an army of lawyers to understand the basic precepts of the law, then it is time for a new law."
One minor point where I differ with @JMcAfreak is the notion of copyright on the word "Droid." I'm 99.9% certain that nobody is allowed under US law to copyright a single word, even for a fictional character name (although this example I would not completely rule out under capricious US copyright law for fictional character names are awarded a great deal of protection in the US), and "droid" is widely understood to be a concept, not a name. I think the word "Android" goes back further in time than Lucas' works (maybe Philip K. Dick coined it?), and "Droid" is clearly a derivative. Importantly, Google is using the term "Android" with impunity now, and to my knowledge they have never obtained a license to use the word from Dick or his heirs. But my real point is that trying to copyright a single word would be very difficult in most nations. If that were possible then it wouldn't be too far of a stretch from there to copyright the color red. Copyright can quickly become ludicrous if taken to logical extremes. If the word is tied to a concept and the concept is fictional and you use the same word and concept in your work then that could be a problem for you so again I agree with @JMcAfreak that you should choose some different words and perhaps also modify the concepts you associate with them from your sources of inspiration. Being inspired by another's work is technically allowed, but where that crosses the line into infringement is decided on a case-by-case basis and is anybody's guess in the US.
I'd also like to see you elaborate on "bloodlines" because I don't know how it's used in your sources, but in general, both bloodlines and a reincarnation technique could be argued to be thousands of years old at least conceptually and as such, should be public domain in any country.