Highest rated episode of the series.
It's worth noting that when Father is reduced back to his original form in Truth's domain, one couldn't fathom such a ridiculous-looking and tiny thing was the cause of everyone's misery.
Truth implies Father could have succeeded if he had not rejected his seven sins.
Father suffers all but his head turning to graphite, so Ed punching a hole in him makes sense.
Greed is the only main character Father killed; plus this was to invoke the same anger in the fans as Ed felt towards Father.