Analyze

This cantrip permanently replaces one prepared spell

Once per fight (A "fight" consists of rolling initiative, this cantrip otherwise cannot be used outside of combat) you can use this cantrip to reveal to yourself one creatures max hp as well as their current hp, and one weakness of said creature (if they have one). 

For every 3 levels your character gains (Level 4, 7, 10, etc) You can target another Creature with this spell.