Indestructible
As long as your devotion to white and black is less than seven, Athreos isn't a creature.
Whenever a creature dies, exile it with a coin counter on it. Each opponent loses 1 life and you gain 1 life.
Whenever Athreos attacks, put a creature card you exiled with a coin counter on it onto the battlefield under your control.

When Attuned District enters, 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.

Creatures you control get +1/+0.
Creatures you don't control get -1/-0.

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

When Avatar of Brilliance enters, 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 you control enters, 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 you control enters, 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 you control enters, 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 you control enters, 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 you control enters, 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.

When Ballot Registrar enters, make a pledge.
Activated abilities of nonland permanents you control cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

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

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

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.

Barreling Bull can't be blocked by creatures with power 2 or less.
When Barreling Bull enters, return a creature you control to its owner's hand.

Barren Ashlands enters tapped.
{T}: Add {B} or {R}.
{5}{B/R}: Barren Ashlands becomes a 3/3 black and red Lizard creature with first strike until end of turn. It's still a land. This ability costs {X} less to activate, where X is your devotion to black and red. Activate only once each turn.