Real Way to use Iso ULT

Its E + X combination
So, first u have to kill someone and take the orb for invulnerability and then Use ult to isolate a fight where u have advantage...
U get a lifeline... Greatest trick against opers and also gives u a lifeline in aim duel with rifle

Note: yes Iso's E can be carried to His domain expansion mode yes

it definitely is the most ideal way to get the best advantage but its just way too situational