So out of all the cards from Dominaria United, the one I'm most excited about for all my primers is
Urza Assembles the Titans for Aminatou.
I have
Oath of Teferi and
The Chain Veil in the deck which are key cards for a number out combos which I outline in the primer. The Third Saga of
Urza Assembles the Titans is "You may activate the loyalty abilities of planeswalkers you control twice this turn rather than only once." means that I get another effect like this.
But on top of this because this is a planeswalker deck in general both the First and Second Saga are really good for value and combos.
First Saga—"Scry 4, then you may reveal the top card of your library. if a planeswalker card is revealed this way, put it into your hand." has a 35% chance of hitting a planeswalker and of course you could use her
+1 if you have a planeswalker in hand already if you were wanting to draw something else for the turn.
All the planeswalkers in the deck are 6 or less mana so the Second Saga "You may put a planeswalker card with mana value 6 or less from your hand onto the battlefield." is guaranteed if you have one in your hand.
The neat thing about these new type of Sagas is that you can choose which one fires first to suit the situation at that exact moment in the game. Then with Aminatou
-1 you get to reset it so that you can keep getting value.
Now unlike
Oath of Teferi and
The Chain Veil which you can play at any time to setup for the future,
Urza Assembles the Titans does have the risk that if you trigger the Third Saga and then you can't use it on subsequent turns. If you specifically don't have Aminatou to reset it back to the First Saga then there is a risk that if you ETB on the Second Saga to put a planeswalker into play, the next turn you get that double planewalker activation but you'll really want to selectively try to plan this for a game winning combo turn.
The Cruelty of Gix is another interesting Saga and in the reanimation version is perfect as you can put any creature into play via searching for
Entomb and then the Third Saga can put that into play. You can Aminatou
-1 to get 2 searches in a single turn which is of course very powerful.
Temporary Lockdown is a good choice for controlling early game play. You can look to get additional triggers from your own creature with mana 2 or less.
Even though your own artifacts can get locked under it, if you Aminatou
-1 the
Temporary Lockdown then they will come into play and in response to the trigger to exile them again you can tap them for mana. You are far more likely to spend the mana than your opponents' getting their artifacts back for the short period.
I think before I'd include it in the deck I'd want to have more ETB creatures that trigger it
The Peregrine Dynamo is another double up effect you can do with planeswalkers. In this instance however you can't use it with Animatou as the commander.
But just like
Lithoform Engine you can look to go infinite with planeswalkers that untap artifacts. So
Teferi, Temporal Archmage,
Tezzeret the Seeker and
Teferi, Who Slows the Sunset.
You need another artifact that gives you the mana to activate them.
With
Teferi, Temporal Archmage and
Tezzeret the Seeker the aim is to either get infinite mana and/or have an artifact that you can tap for some sort of card advantage. For example you can use
Sensei's Divining Top to tap to draw, but in response you can activate
The Peregrine Dynamo/
Lithoform Engine to copy the planewalker ability again and this allows you to stack up as many draws with
Sensei's Divining Top before it actually triggers to go back on top of library.
With
Teferi, Who Slows the Sunset you get infinite life, but you need a land that taps for 2 or more mana if you want infinite mana (or a creature that taps for mana).
Teferi, Who Slows the Sunset is a planeswalker that I've eyed up a bit, but I thought that the ultimate might not be quite good enough for this deck as I don't have that many ways to ultized the untapping each opponent turn as most of the spells are sorcery speed. But drawing an additional 3 cards a turn is nothing to turn nose at, so I could well see making a build that has these cards.