Number one question: Why does your character have 3 names? This is inherently confusing. You're going to have some number of readers wondering, "Wait, you said just Dre and Nezbit were in the room. Who is this Andreas person? Where did he come from?" etc. Remember, you're dedicating months, maybe years of your life to writing this story. You are totally immersed in it. You have everything arranged in your mind. But the reader doesn't know what's in your mind. They just know what they read on the pages. You shouldn't expect the reader to have to study a fiction story like it was a math textbook and figure it out. They should be able to just read the story and understand it.
Well, there could be some mystery that you are deliberately making obscure. If at the beginning of the story you don't want the reader to know that Warlock and Andreas are the same person, and there are various clues and eventually the reader should figure it out, that's different.
Is there some reason why it is essential to the story for this character to have 3 names?
Sometimes we expect different people to address the same person differently. Like I normally expect a character to call his mother "Mom", not "Mrs Miller". But I certainly don't expect the IRS auditor to call her "Mom". (Assuming she is not his mother.)
Writers sometimes vary how they refer to a character for variety. I see the value in this, but it can be confusing. I recall one book I read where a certain character was generally referred to by his first name, and then suddenly at one point the writer refers to him as "the red-head". I was baffled who "the red-head" was. I went searching back through the pages I had just read to find any mention of someone with red hair. I finally figured out from context who he must be talking about, but as far as I could see, he had never mentioned his hair color before.
If it's really necessary to call a character by more than one name, I think you need to make this very explicit to avoid confusing the reader. Like say, "He heard someone behind him shout, 'Hey, Dre!' Andreas realized it must be his brother, because his brother was the only one who called him 'Dre'". Or flat out, "Andreas's enemies called him 'Warlock'".
Remember that even the broadest clue may be missed. If you write, "Andreas walked into the room. Someone called out, 'Hey, Warlock is here!'" Does that clearly tell the reader that Andreas is also called Warlock? No. A reader could surely be forgiven for thinking that you meant that someone warned Andreas that this other person, Warlock, was here, for example. Let me say again, just because you have clear in your mind who is who and what is happening, doesn't mean that that is obvious to the reader.
