Artifact idea

[Elkan]

How about an Artifact usable item "Magic mirror" You have the option to look into it or smash it. When you look into it, it freezes an image of you at the time you use it, and casts door to the past (without quite obviously explaining what just happened to the player) Smashing the mirror casts Revision. But the mirror remains smashed in the revised history. If the player smashes the mirror without looking into it first... well hijnx can ensure, a whole bunch of random anomolies, possibly a temporal rift, or an encouter with a surprised and then suddenly quite worried paradox mage in an alternate timeline who takes the broken mirror very gingerly from you, rewards you somehow "For looking out for me... I think..." possibly after having you dispose of something threatening nearby and then sends you back to where you came from.

(if you implement the last part, the paradox mage is called "Zakastra")