The Mirror of Truth can do a lot of stuff. Like show the owner whatever he/she would want to see. It would also tell the owner only the truth to his/her questions.
The teardrop of Winter can bring about wintery weather like snowstorms and hailstorms.
The heart of Spring can make plants grow to attack or wrap around people.
The bracelet of Monsters can be used to make monsters obey the owners every command or can give the owner whatever type of monster part the owner wishes to have.
The artifact of Change can change the owners body into anything, so basically a shape shifter but mostly only animals.
{Authors Note: I might add more artifacts as I get further into the story.}