As i did with RtR i will do a little analysis of gatecrash's impact on Momir basic. As usual, the cardpool is large so effect will be small, but still here it is:

8drop: Borborgymos, the enraged.

This is probably the most intersting new card due to it being a 8drop, which people are doing the most of on average, and the fact that it provides some interesting dilemmas.

Normally you're not going to have any lands left in your hand when you make this, since the 8drop tends to be the last drop you make. He has the potential to deal 3 damage every turn though if you skip your drop. If the board is relatively stable and the opponent is at 9 life or less i would probably go for burning the opponent out. If you could just survive 3 turns you are winning. However if youre opponent is at higher than 9 i think the plan is going to be too risky generally. A lot can happen in 4 drops from the opponent. You could of course reevaluate from every drop from your opponent, though if you fall behind it isnt easy to catch up.

Another thing to consider is that if your opponent block Borborgymos with a 3/8 for example (Chorus of the conclave) you can shoot by throwing a land at it and the trample over for 2, giving you 3 lands and 9 damage.

Also i would like to live the dream by hitting Borborgymos right after griselbrand, just killing my opponent instantly with a landslide in their face.

The Primordials:

They basicalltý play themselves except for the red one who could require some thought. I think its cool that the two primordials with the best bodies (blue and black) are the ones who dont have any etb-effect in momir. Also the red primordial is worse than zealous conscripts in every other format, but better in momir since its going to steal something ,much more relevant turn 7 while also having a more sturdy body.

Gruul Ragebeast:

Pretty busted, especially since there almost always are some small guys left around, should you hit a guy you dont really want to tangle with something big. It is not fun with you hit a gigantomancer the turn after, though. :P

Angelic Skirmisher:

This card can completely change the entire game, but its probably very important to choose the right mode every combat. I think lifelink is going to be a common mode on offense since first strike is weird because of the very varying p/t creatures has. On defense i imgaine first strike is working better since gangblocking is going to halt the offense. Sometimes if youre chumping duty, lifelink could buy some time.

Aurelia, the warleader:

If this can swing freely, youre probaly winning so no strategy there, However, if this lady is dying on her first attempt attacking, i would be hesitant to cash her in for a large amount of damage. I think just waiting with her until she can set up a lethal attack is better, since the opponent has to thread very carefully not to die as long as the threat of her setting up an extra attack is there. Sometimes a threat is betetr than the execution.

Obzedat, Ghost council:

Very solid as a 5/5 who drains for 2. A word of warning though; please do not exile this guy eot, It will not end well.

Vizkopa confessor:

Two words of advise here; Please do not pay more than 1 life and please (This goes for all extort guys) do not leave mana up for extort. Just felt i needed to say it.

Balustrade Spy/Undercity informer:

No strategy here, i just want to mention that as a momirplayer i am grateful that they are designed like they are. Some people have complained about their design(rightfully so) that they should have milled only opponents, or milled until a nonland is hit. is it possible that wizard designed them the way they did to not ruin momir? I certainly hope so.

Simic Manipulator:

Hes very good, but i would probably try and slowroll his ability for a long time. The way i see it, i rather get one awesome guy than two or even mediumpower guys. because if you have experience from momir, you know that it is the huge over-the top guys who decide most games.

Vizkopa Guildmage:

Be aware that with 2WWBB available you can make a guy pseudounblockable by activating both abilities.

Skargg Guildmge:

Again we come to the threat > execution. As long as this guy is on the board you opponent has to respect the fact that you can make 1 or 2 4/4s and probably needs to leave some guys back. When it is passed to you, you dont even need to activate him but can just make your drop instead.

Legion loyalist:

I never make 1-drops and neither should you, but this guy is a very sweet one since with battalion you can make your entire team unblockable. (All creatures are tokens) I think that this guy is probably the best onedrop you can get in momir ( with the possible exception of Dragonmaster outcast and joraga treespeaker)