Khârn has a +1/+1 counter on it and does not have summoning sickness.
Steps
Activate
Khârn using
Witch Engine's ability by tapping it, adding ({B} magic symbol) ({B} magic symbol) ({B} magic symbol) ({B} magic symbol) and causing an opponent to gain control of
Khârn.
Khârn triggers, causing you to draw two cards.
Activate
Captivating Crew by paying ({4} magic symbol) , causing you to gain control of
Khârn.
Khârn triggers, causing the opponent who controlled it to draw two cards.