This episode was a punch right in the feels
What's his relationship with Marceline?
He was basically her 'father' not genectically but he took care fo her during the mushroom war and they were the only friends either of them had
So he was an adoptive father to her.
So sad he became a tyrant, but at least he felt guilt for not seeing Marceline for so long for many a season.
This episode really made me feel sorry for Ice king ;_;
It really is so sad. *nods in understanding*