During the Phyrexian invasion, Teferi phased the continent of Jamuraa out of reality to protect it rather than fight in the war.
Centuries later, the continent phased back in during the Time Spiral block.
It occurs to me that if the invasion had been successful, the Phyrexians might have still been there when Teferi and Jamuraa returned. He would be in an even more dangerous situation than the one he left.
When Teferi implemented his phasing plan, what did he plan to do when he returned? Did he discuss it at all?