Onyx is a stone that is black as night, its a jungle world, the oni were digging for forerunner weapons, and an army of sentinels were defending it (i just finished reading Ghosts of Onyx)
My Riddle
a ship dark as night
donated by the secret to help with the fight
To the rebel base it did go
only to be betrayed by there own
but in a twist of fate
this ship saved the rubble before it was to late