Omniscience

You may cast spells from your hand without paying their mana costs.

Oracle of the Alpha

Flying
When Oracle of the Alpha enters, conjure the Power Nine into your library, then shuffle.
Whenever Oracle of the Alpha attacks, scry 1.

Futurist Spellthief

Flash
When Futurist Spellthief enters the battlefield, conjure a duplicate of target spell into your hand. That card perpetually gains "You may spend mana as though it were mana of any color to cast this spell."

Displacer Kitten

Avoidance — Whenever you cast a noncreature spell, exile up to one target nonland permanent you control, then return that card to the battlefield under its owner's control.

One with the Multiverse

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library.
Once during each of your turns, you may cast a spell from your hand or the top of your library without paying its mana cost.

Key to the Archive

Key to the Archive enters tapped.
When Key to the Archive enters, draft a card from Key to the Archive's spellbook, then discard a card.
{T}: Add two mana in any combination of colors.