According to Tallulah, Captain Flameheart was a man who lived for battle and bloodshed, and nearly brought the Sea of Thieves to its knees, no one could stand against him, until he simply vainshed. Kinda boggles the mind how someone so powerful, was mysteriously defeated and was never seen again.
So HOW did Flameheart meet his end? Judging by the Seabound Soul Tale, we can see ghostly green flashes of the ship, the Ashen Dragon, and a crew of burning skeletons led by what looks to be an Ashen Lord (who kinda resembles Graymarrow), as they are carrying Flameheart's coffin, the ship was his funeral pyre, and the skeletal crew were honoring his defeat by burying him deep in the caves of Flintlock Peninsula.
I have my theories on how he was beaten...
He was either felled by the Pirate Lord, Ramsey, long ago, or by Captain Pendragon, who had no idea whose soul he had released from the skull, since Stitcher Jim was the man who told him to free the three trapped skulls with his sword.
