Ravnica Allegiance

Hero of Precinct One | Creature | Human Warrior | Whenever you cast a multicolored spell, create a 1/1 white Human creature token. | Bram Sels

Tithe Taker | Creature | Human Soldier | During your turn, spells your opponents cast cost {1} more to cast and abilities your opponents activate cost {1} more to activate unless they're mana abilities. Afterlife 1 (When this creature dies, create a 1/1 white and black Spirit creature token with flying.) | Aaron Miller

Priest of Forgotten Gods | Creature | Human Cleric | {T}, Sacrifice two other creatures: Any number of target players each lose 2 life and sacrifice a creature. You add {B}{B} and draw a card. | Zack Stella

Immolation Shaman | Creature | Viashino Shaman | Whenever an opponent activates an ability of an artifact, creature, or land that isn't a mana ability, Immolation Shaman deals 1 damage to that player. {3}{R}{R}: Immolation Shaman gets +3/+3 and gains menace until end of turn. | Svetlin Velinov

Rix Maadi Reveler | Creature | Human Shaman | Spectacle {2}{B}{R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.) When Rix Maadi Reveler enters the battlefield, discard a card, then draw a card. If Rix Maadi Reveler's spectacle cost was paid, instead discard your hand, then draw three cards. | Sara Winters

Growth-Chamber Guardian | Creature | Elf Crab Warrior | {2}{G}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.) Whenever one or more +1/+1 counters are put on Growth-Chamber Guardian, you may search your library for a card named Growth-Chamber Guardian, reveal it, put it into your hand, then shuffle. | Bram Sels

Incubation Druid | Creature | Elf Druid | {T}: Add one mana of any type that a land you control could produce. If Incubation Druid has a +1/+1 counter on it, add three mana of that type instead. {3}{G}{G}: Adapt 3. (If this creature has no +1/+1 counters on it, put three +1/+1 counters on it.) | Daniel Ljunggren

Lavinia, Azorius Renegade | Legendary Creature | Human Soldier | Each opponent can't cast noncreature spells with mana value greater than the number of lands that player controls. Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell. | Steven Belledin

Biomancer's Familiar | Creature | Mutant | Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana. {T}: The next time target creature adapts this turn, it adapts as though it had no +1/+1 counters on it. | Izzy