Ersta, Friend to All

+1: Create a 3/3 Kavu creature token with trample that's all colors.

−3: Choose up to two target creatures. For each of them, put a number of +1/+1 counters on it equal to the number of colors it is.

−6: Return target multicolored card from your graveyard to your hand. If that card was all colors, draw a card and create two Treasure tokens.

Jared Carthalion can be your commander.

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.

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.

Changeling (This card is every creature type.)

As the game begins, if this creature is your commander, choose two creature types. For the rest of the game, treat those two types like they're the same among your creatures and creature cards everywhere.

, : Choose a creature type. Draw a card for each creature you control of that type.

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.

: Choose a card name that hasn't been chosen from among Disenchant, Braingeyser, Terror, Shivan Dragon, Regrowth, and Black Lotus. Create a copy of the card with the chosen name. You may cast the copy. (You still pay its costs.)