1.) Magical powers are separated into Primal, Divine, Arcane, and Psionic. All creatures, non-martial classes/subclasses, magical races, magic items, and anything else that is applicable is tied to one of these power sources. Various creatures have the ability to sense those with sources of specific power types (for example primal spirit animals can sense practitioners of primal magic or magic items powered by primal energy within a distant depending on the spirit). This is also important when encountering suppression, enhanced, or wild zones that cause magic of certain types to behave differently.
2.) Various creatures gain new abilities, actions, and stats when they reach bloodied. Not all creatures of could but those meant to be greater challenges, changing up the dynamic of combat. A spellcaster might gain a reaction to summon minions at half health, or a creature suddenly goes into a frenzy, gaining the benefits of a barbarian’s rage, or a creature might recharge a power and be able to use it again as a reaction to becoming bloodied.