But seeing as how Lucifer chose not to kill Mary in theSupernaturalseason 13 premiere, whats his plan?

And how will his time in apocalypse world change him?

EW spoke with actor Mark Pellegrino about whats next for the archangel.

That is his entire motivation.

Hes stuck with Mary, having to deal with her and travel through this bizarre world with her.

Its a great dynamic.

I do think theres something in Lucifer that desires to connect to his son on a fatherly level.

I think thats the nature of orphans.

On a level, there is that desire to be a father and to nurture a son.

How does he feel about Michael, whos potentially more powerful than he is?Not even potentially.

This guy is like off the rails, so its pretty scary.

Being bitch-slapped is something that Lucifer is not used to.

You gotta figure that kind of durability came from an eternity of alienation from God.

And despite what Lucifer goes through, he still has that.

Hes out of his league in his way, and thats great.

I like seeing him vulnerable.

Supernaturalairs Thursdays at 8 p.m.

ET on The CW.