Lets take a look what could be considered in a Prophecy of Starscream but I am not convinced all parts will be related to Starscream, but one part, the second line, definitely seems to apply.
First lets pick this section up: He shall arrive with a Titan; and adorned the Titan will be in metal black.
This seems to apply to the Dark Cybertron story arch where a dead metro-titan arrives and basically causes all hell to break loose on Cybertron. Shockwave has manipulated the titan and turned him into a zombie. Often in Cartoons and comics the Death of a transformer is indicated when all colour is gone and they go basically black.
Shockwave's zombie Titan unleashes a death plague on Iacon and many of its residents are marked with blackness which will, if left untreated, kill the afflicted. Starscream was one of the afflicted.
During this part of the Prophecy Bumblebee was killed and lost when crystal city was consumed by a singularity.The He here is may refer to Shockwave. Could also be Nova Prime, Pax/Optimus. But it feels more Shockwave
The second part of the Prophecy is where I feel it applies to Starscream AND The Ghost of Bumblebee. And he shall arrive and stand alone while not alone; and time will rust... and stars will scream. The Stars will Scream seems an obvious finger to Starscream.
As we go further into the story arc - Till All Are One #8 which is in my hot little hands as I write this, we find Starscream talking to the ghost of Bumblebee. Actually through many of the books, Just after the collapse of the Chronal Drive, Destruction of Crystal City and the unexpected death of Bumblebee, Starscream is apparently talking to someone - not there. This appears to indicate that Starscream is a bit messed in the head - I always knew that, but was it more than just a psychosis?
As the stories went on, you would see more and more closeup shots of Starscream with Bumblebee immediately beside him. Starscream appears to have not been trying to hide that he is talking to someone others cannot see. Distance shots often showed Starscream alone or alone with whoever happens to be with him. Of course those who are with him are a little confused by Starscream's random comments. So here it comes clear that although Starscream stands alone, while not actually alone.
In the Annual it becomes apparent that Bumblebee is trapped within the singularity and is still alive - of sorts ?and is communicating to Starscream somehow. Bumblebee's survival could be written as exposure to Ore 14 which was one of the ores that was used to revive the Metro-Titan in the Dark Cybertron arc. The line of the prophecy could also refer to Bumblebee being alone but not alone as well ?but this seems to be more Starscream linked. I do not think the "and time will rust... and stars will scream, " line has come into play, yet. But as of the Annual, They were in the sea of rust... near a singularity - but that may be me digging for connection.
Finally for this section, I am very curious as to why and how Bumblebee and Starscream have this connection. It is indicated that Starscream does not believe Bumblebee is anything more than his imagination - His way of coping with guilt for murdering his friend, Fear of Megatron's return and of him possibly screwing up the single thing he ever wanted in life - which was to rule. To which bumblebee said We are stronger together than apart.
On a side note: as much as I generally dislike bee - I do like the characterisation they have wit this one
So far this part remains unrevealed thus far. "And the symbol of the Uncreator shall be clear... and his gaze shall unravel the legacy of Primus."
It could be Unicron, It could be Nova Prime, who knows maybe the legacy of Primus is the return of all living primes to Cybertron who knows this will get updated as soon as I know.
Keep in mine these are Sunstar's interpretation of this Prophecy and it is in no way the truth