How did this happen? Being stripped of his power, basically banished from being a part of the Goetia family, left with the ability to only make a portal allowing him to travel between Hell and Earth.

Stripped of all status, demons no longer fearing him, only having respect for the select few humans who still worshipped him on earth.

It was difficult to go to earth since his human disguise took more energy to use now. Leaving him to make tough decisions of where to go.