Oh, if only Kirk would Karate chop. No... the only thing better than a good Red Shirt death is the Star Trek Punch!
To the kidneys... Do Gorn have kidneys?
It is so iconic that Lower Decks did an entire bit about how the ship's #1 beats a huge alien using only "Kirk-Fu"
Great read, and so much fun. Glad your boy got to set his phasers to kill! The Xenomorphs aren't likely to succumb to Kirk's seduction skill.
Not sure how old your boy is, but perhaps you could make some "science discovery" cards that show something gross. Spock analyzes the face hugger and you get this picture:
Explaining the acid blood could show real acid eating away at an orange for effect?
I almost always think in pictures, and as the old saying tells us "a picture is worth a thousand words." A gross picture is usually worth at least three thousand words, in my experience