Kaya, Orzhov Usurper

[+1]: Exile up to two target cards from a single graveyard. You gain 2 life if at least one creature card was exiled this way.
[−1]: Exile target nonland permanent with mana value 1 or less.
[−5]: Kaya, Orzhov Usurper deals damage to target player equal to the number of cards that player owns in exile and you gain that much life.

Ravnica Remastered

+1: Exile up to two target cards from a single graveyard. You gain 2 life if at least one creature card was exiled this way.
−1: Exile target nonland permanent with mana value 1 or less.
−5: Kaya, Orzhov Usurper deals damage to target player equal to the number of cards that player owns in exile and you gain that much life.

The List

Ravnica Allegiance

+1: Exile up to two target cards from a single graveyard. You gain 2 life if at least one creature card was exiled this way.
−1: Exile target nonland permanent with converted mana cost 1 or less.
−5: Kaya, Orzhov Usurper deals damage to target player equal to the number of cards that player owns in exile and you gain that much life.

Mythic Edition

Ravnica Allegiance Promos

If a permanent has {X} in its mana cost, X is considered to be 0.

Kaya's last ability causes you to gain life equal to the number of cards the target player owns in exile, even if an effect causes her to deal more or less than that amount of damage to that player.

Tokens that aren't a copy of something else don't have a mana cost. Anything without a mana cost normally has a mana value of 0.