Nerys Myk wrote:
McCoy doesn't mention anything about blood composition. Besides, Original Khan and nuKhan are not the same people.
He doesn't have to. The human healing process centers around blood. Khan was seconds away from death in "Space Seed", that he could recover quickly and completely without McCoy lifting finger means he has "magic blood".
Original Khan and nuKhan are the same people. Khan comes from before the timeline split in 2233.
Not every little thing needs a piece of dialog to fully "explain" it. The viewer should be able to connect the dots on their own.
Spock didn't have mental powers until they were retconned onto him a few episodes into the series - leading one to wonder why he never attempted a neck pinch on Garry Mitchell, or why he, a strong telepath, wasn't affected by passage into the barrier at the edge of the galaxy.
Conversely, the addition of Khan's "super blood" has no similar retroactive impact on Space Seed or Wrath of Khan, and actually ties in neatly to Arik Soong's comments to Jonathan Archer about how the repressed genetic engineering technology could have saved Archer's father during the ENT Augment trilogy, and how the genetically engineered are free of illness and live 3 times longer than humans.