Recap / Star vs. the Forces of Evil S3 E12 "Demoncism"
Star and Ponyhead try to stop Tom from getting a "demoncism".
Be Yourself: Tom willingly decides to undergo a demoncism to remove his demonic energy in the hopes of it alleviating his anger issues for Star's sake. After seeing what a demoncism did to Pony Head's ex, fundamentally changing who he is as a person, Star resolves to put a stop to it. After Tom awakens post-demoncism in agony and is told that it would just be the first session in a lengthy regimen, Star assures him the desire and effort to improve himself is the important part.
Call-Back: Star decides to collect on Tom's corn-shake offer from the end of "Club Snubbed".
Cannot Keep a Secret: It doesn't take much prodding for Star to get Ponyhead to blab about Tom's demoncism.
Cooldown Hug: Star gives one to Tom when his demoncism apparently gets out of hand.
Correlation/Causation Gag: Star is punching a tree when an explosion caused by Tom's demoncism occurs nearby. Pony Head thinks it was caused by Star punching too hard.
Empty Shell: Unfortunately, the side effect of getting a Demoncism is that the subject is robbed of all emotion and any semblance of personality.
Overly Nervous Flop Sweat: Ponyhead is seen sweating profusely while resisting the effort to outright tell Star about Tom's demoncism.
Picture-Perfect Presentation: Star looks at a video of Seahorse as a punk rocker smashing thing onstage. She then puts the phone aside to look at present-day Seahorse, a mild-mannered customer service representative with Nerd Glasses.
Really Gets Around: When Ponyhead suggests they ask her ex where demoncisms are held, a frustrated Star asks "Which ex?" She then apologizes for sounding so harsh and judgmental about it.
"Shaggy Dog" Story: Tom's demoncism is a success... but they were only able to remove one of the thousands of demons inhabiting him, and getting rid of them all would require a thirteen-year regimen. Tom decides it's too risky and not worth the effort.
Ship Tease: At the end of the episode, Tom and Star end up holding hands, much to the surprise (and annoyance) of Ponyhead.
Stepford Smiler: After his demoncism, Seahorse is left a mild-mannered doormat who cheerfully parrots customer-service stock phrases no matter what others seem to say.
Too Spicy for Yog Sothoth: Presumably, an average demoncism doesn't involve a giant forest fire and the ritualists running and cowering for their lives. Tom is apparently so powerful that removing his demonic energy would require a thirteen year regimen of demoncisms.
Weirder Than Usual: Star notes this of Tom at the beginning of the episode, because it's very unlike Tom to avoid her.