I have discovered the final raid boss for Wraith of the machine in the grimore cards the boss is [spoiler]Sepiks Re-Perfected[/spoiler] Theres lots of data proving this mostly in the grimore cards about sepiks prime and the one pilot servator lore mini games The final boss will conclude with you killing sepiks once and for all until he goes to his throne world where you have to kill his soul Once hard mode is released and you kill him for the last time this happens [spoiler]he blows up into a million pieces then his dust is vaporized by the sun, which is then super nuked, only to reveal sepiks has escaped and will return in Destiny 2: The re-re-re-re-re-re-return of Sepiks Ultra Superbly Adequate Mega Perfected Prime [/spoiler]