I'm sure this is only a fraction of the interesting cards in the set, but there's already so many. I could have picked a few more from the spoiler cards, but these drew my eye the most. I did recently pick up commander again, which makes this set waaaaay more interesting than when I just had my cube...
Blackblade Reforged 
Legendary Artifact — Equipment
Equipped creature gets +1/+1 for each land you control.
Equip legendary creature
Equip
Broken Bond
Sorcery
Destroy target artifact or enchantment. You may put a land card from your hand onto the battlefield.
Darigaaz Reincarnated
Legendary Creature — Dragon
Flying, trample, haste
If Darigaaz Reincarnated would die, instead exile it with three egg counters on it.
At the beginning of your upkeep, if Darigaaz is exiled with an egg counter on it, remove an egg counter from it. Then if Darigaaz has no egg counters on it, return it to the battlefield.
7/7
Dark Bargain
Instant
Look at the top three cards of your library. Put two of them into your hand and the other into your graveyard. Dark Bargain deals 2 damage to you.
Deep Freeze
Enchantment — Aura
Enchant creature
Enchanted creature has base power and toughness 0/4, has defender, loses all other abilities, and is a blue Wall in addition to its other colors and types.
Demonlord Belzenlok
Legendary Creature — Elder Demon
Flying, trample
When Demonlord Belzenlok enters the battlefield, exile cards from the top of your library until you exile a nonland card, then put that card into your hand. If the card's converted mana cost is 4 or greater, repeat this process. Demonlord Belzenlok deals 1 damage to you for each card put into your hand this way.
6/6
The Eldest Reborn
Enchantment — Saga
(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Each opponent sacrifices a creature or planeswalker.
II — Each opponent discards a card.
III — Put target creature or planeswalker card from a graveyard onto the battlefield under your control.
Fight with Fire
Sorcery
Kicker
(You may pay an additional as you cast this spell.)
Fight with Fire deals 5 damage to target creature. If this spell was kicked, it deals 10 damage divided as you choose among any number of targets instead.
(Those targets can include players and planeswalkers.)
Firesong and Sunspeaker
Legendary Creature – Minotaur Cleric
Red instant and sorcery spells you control have lifelink.
Whenever a white instant or sorcery spell causes you to gain life, Firesong and Sunspeaker deals 3 damage to target creature or player.
4/6
Grand Warlord Radha
Legendary Creature — Elf Warrior
Haste
Whenever one or more creatures you control attack, add that much mana in any combination of R and/or G. Until end of turn, you don't lose this mana as steps and phases end.
3/4
Hallar, the Firefletcher
Legendary Creature — Elf Archer
Trample
Whenever you cast a spell, if that spell was kicked, put a +1/+1 counter on Hallar, the Firefletcher, then Hallar deals damage equal to the number of +1/+1 counters on it to each opponent.
3/3
Helm of the Host
Legendary Artifact — Equipment
At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary if equipped creature is legendary. That token gains haste.
Equip
Howling Golem
Artifact Creature — Golem
Whenever Howling Golem attacks or blocks, each player draws a card.
2/3
Kamahl's Druidic Vow
Legendary Sorcery
(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Look at the top X cards of your library. You may put any number of land and/or legendary permanent cards with converted mana cost X or less from among them onto the battlefield. Put the rest into your graveyard.
Marwyn, the Nurturer
Legendary Creature — Elf Druid
Whenever another Elf enters the battlefield under your control, put a +1/+1 counter on Marwyn, the Nurturer.
T: Add an amount of G equal to Marwyn's power.
1/1
The Mirari Conjecture
Enchantment — Saga
(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Return target instant card from your graveyard to your hand.
II — Return target sorcery card from your graveyard to your hand.
III — Until end of turn, whenever you cast an instant or sorcery spell, copy it. You may choose new targets for the copy.
Muldrotha, the Gravetide
Legendary Creature — Elemental Avatar
During each of your turns, you may play up to one permanent card of each permanent type from your graveyard. (If a card has multiple permanent types, choose one as you play it.)
6/6
Naban, Dean of Iteration
Legendary Creature — Human Wizard
If a Wizard entering the battlefield under your control causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
2/1
Oath of Teferi
Legendary Enchantment
When Oath of Teferi enters the battlefield, exile another target permanent you control. Return it to the battlefield under its owner's control at the beginning of the next end step.
You may activate the loyalty abilities of planeswalkers you control twice each turn rather than only once.
!!! Teferi joins the Gatewatch!
Phyrexian Scriptures
Enchantment — Saga
(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Put a +1/+1 counter on up to one target creature. That creature becomes an artifact in addition to its other types.
II — Destroy all nonartifact creatures.
III — Exile all cards from all opponents' graveyards.
Precognition Field
Enchantment
You may look at the top card of your library.
(You may do this at any time.)
You may cast the top card of your library if it's an instant or sorcery card.
3: Exile the top card of your library.
Settle the Score
Sorcery
Exile target creature. Put two loyalty counters on a planeswalker you control.
Slimefoot, the Stowaway
Legendary Creature — Fungus
Whenever a Saproling you control dies, Slimefoot, the Stowaway deals 1 damage to each opponent and you gain 1 life.
: Create a 1/1 green Saproling creature token.
2/3
Teferi, Hero of Dominaria
Legendary Planeswalker — Teferi
<+1>: Draw a card. At the beginning of the next end step, untap two lands.
<−3>: Put target nonland permanent into its owner's library third from the top.
<−8>: You get an emblem with "Whenever you draw a card, exile target permanent an opponent controls."
<4>
One word:
Brainstorm :eek:
Territorial Allosaurus
Creature — Dinosaur
Kicker
(You may pay an additional as you cast this spell.)
When Territorial Allosaurus enters the battlefield, if it was kicked, it fights another target creature.
5/5
!!! Another dinosaur!
Whisper, Blood Liturgist
Legendary Creature — Human Cleric
, Sacrifice two creatures: Return target creature card from your graveyard to the battlefield.
2/2
