As to the Space Phantoms and Immortus, it was all part of the plot to drive Wanda nuts and make her susceptible to Immortus controlling her.
We should point out the Space Phantoms weren't part of Byrne's Immortus drives Wanda nuts plot. Byrne's Horton is meant to be Horton. Busiek retconned him and various other characters into a space phantom thus ruining far more stories than Englehart or Byrne put together.