User blog comment:Tommy,Klaus&Kol2012+/Will the writers kill off michael in the midseason finale episode-the spear?/@comment-1031724-20181218073007/@comment-1031724-20181219070653

And they made him main villain two seasons in a row, last time they did that was Lilith in Seasons 3 and 4. Even Crowley had a season between the two seasons he was main villain. Though Michael DID share Season 13 with Asmodeus, but some consider him secondary coz he was killed six episodes before the finale.