Black has two of the strongest one mana cards in Standard, a third that is nearly as good, plus a combat trick that is growing in popularity. There are two creature cards that I needed to consider, even though they are both a bit situational or require a certain kind of deck to be even better I think they deserve to make the list.
Creatures *Deadeye Tracker - This is a 1/1 pirate for one black mana that has a secondary ability that can be quite useful if given the chance to use it. For 1B,
Deadeye Tracker can
exile two cards from your opponents library AND perform an
explore. This combo of effects is quite strong, if you ever get a chance to use it.
Explore is nice, but currently not a ability that wins games. Exiling targeted cards from the graveyard is really good against a couple of the upper tier decks in Ixalan Standard. The problem here is those players are quite aware of this and the result is
Deadeye Tracker does not often get to perform effectively. The ability requires DT to tap, which gives your opponent 2 turns to remove the threat. Even with the recommendation that this can be a sideboard card the best I can do is give
Deadeye Tracker an Honorable Mention.
Dread Wanderer - A 2/1 zombie for one Black mana is a great card, but it comes into play tapped. That basically means it cannot be a blocker on the next turn, but if you are playing with
Dread Wanderer you are not looking to block anyways, right?
Dread Wanderer also has the ability, at Sorcery speed, to come back into play from your graveyard, tapped. You have to have only one card or less in your hand at the time, but an aggressive black deck that can really use
Dread Wanderer will find itself playing of the top of the deck often enough that this really is not a hard circumstance to be in, plus there are currently a number of good situations for the zombie tribe that can quickly make DW even more
dangerous than a 2/1.
SpellsDuress - A reprinted card that has spent a little bit of
time out of Standard, but is back again to cause grief. Looking at your opponents hand and removing any non-land, non-creature card to their graveyard is just good. Always has been, always will be. Often
Duress is the best way for a deck to
disrupt your opponents' strategy. Are there some top tier decks that this is less effective against? Sure, but that is why we have a sideboard strategy. I believe this is a top 5 card in the current Standard.
Fatal Push -
Fatal Push has pushed its way into the top 10 list of pretty much every competitive format in Magic. Granted, it is not effective against any creatures with a casting cost higher than 4, and a bit trickier to use against three and four mana creatures, but there are no adverse side effects to using it. No life or land gained by your opponent, no creature sacrifices (at least as an official cost), and no color restrictions.
Fatal Push is the best one mana spell in the Ixalan Standard format.
Harsh Scrutiny - Here we have a new twist on an old friend. For one black mana, we get to see target opponents hand, and remove a creature card from there to their graveyard. It is relegated to Sorcery speed, but the new twist is the Scry that follows. Again, with the current Standard format running so creature heavy, it is going to be really hard to miss with this spell. I have only seen 2 opponents play this card against me, but I think this card deserves more play. This card gets an Honorable Mention for the top 5 cards.
Skulduggery - An instant that provides a 2 point shift on the fly. This is a shining example of a great combat trick. There are so many ways
Skulduggery can influence combat. Chump blocking their 3/3 first strike with your 2/2
lifelink, is exactly what your opponent was hoping for. Then you cast
Skulduggery, gain 3 life instead of 2, and your creature is wiping of the dust while their first striker gets buried in the graveyard. Keep an eye on this card as you will be seeing it more with the
rise of mono black decks.
SideboardThese are not the good black spells you were looking for....