Chancellor of the Mulligan

When Battle Myrsphere enters the battlefield, reveal cards from the top of your library until you reveal a battle card. Put it onto the battlefield, and the rest on the bottom of your library in a random order.

Whenever Battle Myrsphere attacks, you may tap X untapped battles you control (so they're oriented like a regular Magic card). If you do, Battle Myrsphere gets +X/+0 until end of turn and deals X damage to the player or permanent.

You may reveal this card from your opening hand. If you do, at the beginning of your first upkeep, look at the top four cards of your library. You may put one of those cards back on top of your library. Exile the rest.

When you cast this spell, exile target permanent that's one or more colors.

Reveal this card as you draft it. Reveal the next card you draft and note its name.

When this creature enters, you may search your hand and/or library for a card with a name noted as you drafted cards named Aether Searcher. You may cast it without paying its mana cost. If you searched your library this way, shuffle.

Prototype — 3/2

At the beginning of your upkeep, return target creature card with power less than this creature's power from your graveyard to the battlefield. Its base power perpetually becomes equal to this creature's power.

Flying

This creature enters with three +1/+1 counters on it.

At the beginning of your upkeep, you may remove any number of +1/+1 counters from this creature. If you do, create that many 1/1 colorless Tetravite artifact creature tokens. They each have flying and "This token can't be enchanted."

At the beginning of your upkeep, you may exile any number of tokens created with this creature. If you do, put that many +1/+1 counters on this creature.

At the beginning of each player's upkeep, that player reveals the top card of their library. If it's an artifact, creature, enchantment, or land card, the player may put it onto the battlefield.