Best minor artifact?

[Vagabond?]

I'm playing a level 19 Artisan, and I want to know, what do you think the best Minor Artifact is? I want to know that I made a decent decision when I choose my artifact, and want it to actually be useful. Something useful for a more mage-like character, one who uses primarily magic items.

[Avoron]

The most powerful are also the least reliable: a sphere of annihilation or a harrow deck of many things.

Personally, I'm a fan of the id portrait. It provides a unique and powerful benefit that cannot be duplicated by any other sort of magic. Not only does the ability to create alter-egos of oneself (with completely different abilities) provide a lot of versatility and influence, it is a fascinating roleplaying opportunity.

[Scythia]

Especially for a caster type, the obvious choice that comes to mind is Staff of the Magi. Having a decent number of charges makes it useful, it's got a decent spell selection, it's absorbing ability provides excellent spell defense and additional power, and you can self-destruct if you ever want to.

[Fourshadow]

When they say 'minor', I'm thinking smaller than that. Like the Morrow-whatsit, the other side of the Totemtrix. I like that thing. Not too powerful and very thematic.