These words are in scribblenauts unlimited DEADLY gun, DEADLY flintlock, basically add deadly before anything and it's damage will be multiplied by 15 in S unlimited and 10 in S unmasked.
Then there is LOYAL, add this before any evil persons name (except for Edison Yan) and they'll become your followers, they'll kill any hostile NPC's.
Apply SUPER strength to yourself and you'll be able to kill (almost) anyone in one punch!
Apply MAGIC to yourself and you'll be able to use the CAST MAGIC action!
Type MAXWELL'S NOTEBOOK and you'll spawn a random object with random adjectives, a great way to increase vocab!
This is pretty basic, apply the INVINCIBILITY adjective to become invincible, doesn't work in all missions.
IF YOU'RE FEELING LAZY (DON'T WANNA KILL THE BAD GUY YOURSELF) I RECOMMEND YOU GET A CLONE GUN, SPAWN A "LOYAL FAST POWERFUL ARMED OPERATIVE" AND KEEP ON CLONING HIM.