Necrotic Wound
Instant
Undergrowth — Target creature gets -X/-X until end of turn, where X is the number of creature cards in your graveyard. If that creature would die this turn, exile it instead.
The assassins of the Ochran distill toxins from the remains of their previous victims.
Randy Vargas
Foundations Jumpstart (J25)
• #470Rulings
If you have no creature cards in your graveyard, the target creature gets -0/-0, and it will still be exiled if it would die this turn.
(wotc • 2018-10-05)
Necrotic Wound's replacement effect will exile the target creature if it would die this turn for any reason, not just immediately after Necrotic Wound resolves.
(wotc • 2018-10-05)
The value of X is determined only as the undergrowth ability resolves. If the number of creature cards in your graveyard changes later in the turn, the target creature is unaffected.
(wotc • 2018-10-05)
Creature cards with other types, such as artifact creature cards, count for undergrowth abilities.
(wotc • 2018-10-05)
Because tokens aren't cards, they never count for undergrowth abilities.
(wotc • 2018-10-05)
Rulings
If you have no creature cards in your graveyard, the target creature gets -0/-0, and it will still be exiled if it would die this turn.
(wotc • 2018-10-05)
Necrotic Wound's replacement effect will exile the target creature if it would die this turn for any reason, not just immediately after Necrotic Wound resolves.
(wotc • 2018-10-05)
The value of X is determined only as the undergrowth ability resolves. If the number of creature cards in your graveyard changes later in the turn, the target creature is unaffected.
(wotc • 2018-10-05)
Creature cards with other types, such as artifact creature cards, count for undergrowth abilities.
(wotc • 2018-10-05)
Because tokens aren't cards, they never count for undergrowth abilities.
(wotc • 2018-10-05)