Providence of Night

Flying

Whenever this creature deals combat damage to a player, you may cast a spell from your hand without paying its mana cost.

Whenever you cast a signed spell or play a signed land, copy it. (A signed card is a card signed by its artist, designer, or someone else it's strongly associated with.)

Discard a signed card: Destroy target creature with a name that has a five or fewer letter length difference from the person who signed the discarded card.

Flying

When Niv-Mizzet enters, reveal the top ten cards of your library. For each color pair, choose a card that's exactly those colors from among them. Put the chosen cards into your hand and the rest on the bottom of your library in a random order.

Legendary creatures you control get +X/+X, where X is the number of legendary creatures you control.

Whenever you cast a legendary spell from your hand, exile cards from the top of your library until you exile a legendary nonland card with lesser mana value. You may cast that card without paying its mana cost. Put the rest on the bottom of your library in a random order.

Flying, hexproof from multicolored

Whenever Niv-Mizzet deals combat damage to a player, it deals X damage to any target, target player draws X cards, and you gain X life, where X is the number of different color pairs among permanents you control that are exactly two colors.

If The Snapstone Wielder is your commander and your deck contains no land cards, your starting hand size is four and for the rest of the game, at the beginning of your upkeep, you get a mana counter. During each of your turns, you can spend mana of any color equal to the number of mana counters you have. (You want mana on opponent's turns, you're on your own. Who needs instant-speed interaction—)

Whenever The Snapstone Wielder enters or attacks, cast a random nonland Magic card without paying its mana cost. If it has targets, choose the targets at random.