Ok so, from the trailer we can deduce from the song sung by the legend Johnny Cash, that there will ghost riders in the sky. But what does this mean? "Ghost riders in the sky". Well firstly we're going to have to go deep, balls deep.
"In the sky" this part is the easy to swallow bit, mass effect being the space game it is means that "the sky" means "in space".
Now for the hard bit, "ghost riders", in 2007 we were blessed with the masterpiece that is Ghost Rider (2007), what else came out in 2007? Mass Effect 1 the original mass effect.
Now, who is the ghost rider? John Blaze, AKA Nic "the cage" Cage.
Now as both protagonists were the main characters, and both the lead kiddo's in the trailers were indeed Johnny blaze and commander shephard, we can gauge that the main character of mass effect andromeda is
[spoiler]Nic Cage it was Nic Cage the whole time we just hadn't realised it yet get that hype train steaming. [/spoiler]