So I am currently making a top-down hack-and-slash game, like a faster-paced version of the Legend of Zelda games. I had been wanting to add something unique to Keys in the game since the whole locked doors system can get a bit stale at times.
I had recalled an enemy from Super Mario 2, a cursed key that when taken will summon an enemy that will pursue the player until the key is used. (Since it was in a 2D platformer the AI wouldn't worry about walls and would behave in a way that would only make sense in 2D platformers.)
I wanted to reference this partially with a key that would summon some sort of enemy that (similar to the one in Mario 2), would pursue the player until using or dropping the key. My game is more futuristic/technology-based, so the enemy couldn't be a phantom that just floats around. How could I make the concept of an enemy like this?