Exile target creature.
Scry 1.

When Attuned District enters the battlefield, scry 2.
Whenever you scry, you may pay {1}. If you do, create a 0/0 colorless Construct artifact creature token, then put X +1/+1 counters on it, where X is the number of cards you looked at.

When Audacious Roughrider enters or leaves the battlefield, exile the top card of your library. Then you may discard a card. If you do, put the exiled card into your hand. If you don't, create a Treasure token.
Wander {4}{R}{R}

Favored
Whenever a legendary creature you control attacks, create a tapped and attacking token that's a copy of that creature, except it's not legendary and is an enchantment in addition to its other types.

Whenever Augmented Ruffians attacks, integrate the top card of defending player's library.
Augmented Ruffians gets +1/+1 for each card integrated onto it.

Whenever another nontoken creature you control dies, you may mill a card. If you're ancient, instead you may draw a card.

{1}, Sacrifice Auto Sifter: Search your library for a basic land card, reveal it, put it into your hand, the shuffle.

Target creature you control gets +2/+0 and gains first strike until end of turn. If it's attacking, create a 1/1 white Human creature token that's tapped and attacking.

When Avatar of Brilliance enters the battlefield, you may cast target instant or sorcery card in your graveyard with mana value X or less without paying its mana cost, where X is the number of differently named lands you control. If that spell would be put into your graveyard this turn, exile it instead.

Flying
Drop — Whenever Avatar of the Airwaves or another creature enters the battlefield under your control, if the entering creature was cast and you didn't cast any creature spells during your last turn, create a token that's a copy of target non-Avatar creature you control.

Menace
Drop — Whenever Avatar of the Decks or another creature enters the battlefield under your control, if the entering creature was cast, sacrifice a permanent unless you didn't cast any creature spells during your last turn.

Vigilance
Drop — Whenever Avatar of the Festival or another creature enters the battlefield under your control, if the entering creature was cast and you didn't cast any creature spells during your last turn, you may have your life total become the total power and toughness of creatures you control.

Haste
Drop — Whenever Avatar of the Moshpit or another creature enters the battlefield under your control, if the entering creature was cast and you didn't cast any creature spells during your last turn, discard your hand, then draw three cards.

Reach
Drop — Whenever Avatar of the Rave or another creature enters the battlefield under your control, if the entering creature was cast and you didn't cast any creature spells during your last turn, return up to two target cards from your graveyard to your hand.

You don't lose unspent mana as steps and phases end.
At the beginning of your end step, if you've spent at least five mana to cast spells this turn, draw a card. If you've spent at least ten, create a 10/10 green Elemental creature token. If you spent at least twenty, you gain 20 life. If you spent at least fifty, you win the game.

Flying
Favored
Whenever your Champion attacks, you may double its power until end of turn. If you do, sacrifice it at the beginning of the next end step.

Vigilance, lifelink
Ward—{2}, Pay 2 life.
Azantium, Perfect Creation has all activated abilities and triggered abilities of other artifacts you control.

Return target creature to its owner's hand.

When Bangtan Security enters the battlefield, target creature gets +2/+0 and gains indestructible until end of turn.

When Banish to the Isle enters the battlefield, exile up to one target nonland permanent you don't control until Banish to the Isle leaves the battlefield. You gain 3 life.

Up to X target creatures you control each get +1/+1 until end of turn. Untap those creatures.

When Barbarous Roughrider enters or leaves the battlefield, each opponent loses 2 life unless they sacrifice a nontoken creature.
Wander {4}{B}{B}

Trample
Solidarity

Flash
At the beginning of your end step, if you've cast no spells this turn, you may draw a card, then discard a card.