Another batch of spoiler reviews

White:

Citadel Siege-
This is expensive, but the utility might make it useful for someone who simultaneously wants to grow creatures vertically and have way to manage opposing large blockers. This is probably the Siege that I like the least for EDH. Four mana buys you so much in this format that I don't think this ever really justifies itself.

 Lightform-
This is an interesting card. I'm not sure how much I love WW in the cost, but paired with library manipulation this could give someone a nasty surprise when flipped. I could see it in Uril or Brenna, but they would have to be designed in such a way as to have back up creatures to voltron up. The normal use of this is as a 3 mana 2/2 flying lifelink, which just isn't good enough. It can't even fall back on tribal synergies.

Monastery Mentor-
Chapin did a whole Select article on this guy for SCG. I don't have much to add, except that this guy will be a lightning rod the instant you cast him. One thing I'd like to play him with is tons of artifact mana and hurkyl's recall, or something that has inherent global haste. He goes into Jor Kadeen, Narset, or mono-white anthem generals. He's going to be expensive, so keep that in mind if you are playing on a budget.

Wandering Champion -
She'll kick you apart, she'll kick you apart.
This has very few possible homes, but I think I would play it in those places more often than not. W/R loves to get some velocity going, and with multiple opponents getting to connect is going to be pretty frequent. Pair this with Land Tax and you have a pretty steady stream of fuel for pitching. She also functions really well with equipment since getting to keep digging is going to work out for you. W/R generals are going to want her more than W/U or W/R/U generals are, but digging into counter magic is going to be helpful.

Blue:

Marang River Prowler-
The prowler costs a lot, and you have to pay that cost every time you want to re-cast him. He pairs pretty well with skullclamp, but so do lots of cards. I don't see him being good enough in U/B since you can have access to Bloodghast or Recurring Skeleton, but in U/G he might find a more solid home. There's also the density of effect for a deck like Grimgrin which just wants as much of this as it can get. Prowler is marginal but might be played because he just does a fairly unique thing.

Monastery Siege-
My favorite siege, this gets a huge nod because of its mana cost. This is cheap, flexible and powerful. The fact that it draws you a card means it interacts with dredge and draw triggers. It lets you put things into your graveyard, and it provides a significant amount of velocity. Its other mode also protects itself as well as all your other permanents from spot removal. This has applications in any blue deck that wants to draw a lot of cards or protect itself from spot removal, which is basically all of them.

Supplant Form-
This card will be an EDH staple. Its the same principle as Gather Specimens, but the timing isn't nearly as restricted. I see many instances of someone cheating out an Avenger or Eldrazi and getting blown out by this card. There are tons of fatties in any given game of EDH and this can even lend itself to loops pretty easily with enough mana. This is a battlecruiser card and will lead to tons of fun moments when someone thinks their winning and gets the game flipped upside down on them.

Black:

Battle Brawler-
Orc Tribal Ho!

Mardu Strike Leader-
This dude is fairly vanilla for EDH. Dash is cool but there are better bodies, better Dashers, and better token makers. Maybe if you are doing some hardcore comes into play non-sense in R/B then this guy could be a factor,  like a Flamerush Rider in number of bodies provided. Unlike the Rider, this guy's tokens hang around, letting you feed them to skullclamp or another sac outlet for value later on. Again, all the on attack triggers benefit from the multiplayer nature of edh. He might find a home in some Jund-y deck like Prossh.

Red:

Flamewake Phoenix-
More red value! yay! This creature is patently absurd. We have seen in the past that 2/2 flying haste for 3 mana is pretty good on its own. Getting it back into play tapped and attacking for R whenever you can attack is going to be really annoying to deal with for your opponents. Factor in that your opponents don't need to kill it, that you can eat it with Gargadon or whatever payoff suits your fancy, and we have a engine going on. It basically can only ever block the first time you cast it, so there is that. And sometimes its going to suicide into three opposing players that can block it, but getting it back is soooooo cheap. I can think of plenty of R/X decks that want more consistent food.

Hungering Yeti-
5 mana 4/4s with conditional flash are not where I want to be.

Green:

Abzan Kinsguard-
4 mana 3/3s with conditional lifelink are not where I want to be.

Frontier Siege-
This one is more conditional that the others, but is potentially very powerful. Its reminiscent of Skyshroud Claim the first time you cast it, adding back half its cost in the next main phase. The next turn it generates four mana, all of it colored. This mode alone makes it an auto-include in Omnath. I don't think you'll often see the other mode picked, but it tells us how much flying the next set is going to involve if green is getting an effect that relies on flying creatures. This is a good card, its just all about if you can use the mana at the somewhat awkward intervals you get it.

Multicolor:

Daghatar the Adamant-
This guy is basically a directly worse version of Ghave in EDH. He costs more to activate, his activation costs colored mana, and it does less. If you could play him in W/G or W/B then he'd probably be fine. If he cost 1 less then you play him in Tiny Leaders and he'd be fine. As is I don't see him fitting into the format anywhere when for 1 mana more you get to play one of the best generals in the format.

Shu Yun, the Silent Tempest-
For half the mana of Narset you get a very aggressive general. I don't know if I like him more or less than Narset for Voltron. On the one hand he's a threat much earlier and is more explosive. On the other hand, Narset has the best word for a general that you are trying to load up on: Hexproof. Either way this guy will be played as a general and be good. He can probably be one of your creatures in Narset and vice versa. One thing this guy can do is be played as a Tiny Leader, which is something I'll talk about more extensively in its own post.

Torrent Elemental-
This guy is pretty stout in combination with effects like Delve or something else that exiles for value. I'm thinking of putting him in my Mimeoplasm deck since the on-attack trigger turns off blockers and getting to re-cast him afterward is good value. It also helps fight through some amount of graveyard hate. The only downside is how expensive he is.

Brutal Hordechief-
Hello Nurse!
This guy is like Hellrider, except the trigger is much stronger, but he doesn't get to attack immediately. For EDH I'm really sad you can't play him in Oloro :(. We almost have enough  attack oriented stuff in Mardu to make a solid deck. The wording of the trigger lets it penetrate protection and hexproof of the defending player, but luckily they did not word it in such a way as to be broken by draining EACH opponent. The activated ability is expensive but can be activated during other players combat to interfere with blocking decisions as well as on your turn to let you get through lots of damage.

Shaman of the Great Hunt-
Another Hellrider? What is it with Khans and great four mana aggressive cards?
Anyway, this guy is definitely great. He's still held back by the color identity rules, but his activated ability is a very scary threat, and his triggered ability is also very scary. That he can build creatures up to counting for his activated ability is super cool. I think this guy is going to be solid and interesting, which is the best kind of card. He'll see play in just about every Temur deck.

Dromoka the Eternal-
Mana efficient dragons with upside are cool. I like her, but I don't know where I'd want her. She's obviously better the more you care about the counters or the more dragons you have. I doubt I'd want to play her as a general over the crazy depth of G/W generals there are out there, but she could see play in dragon focused decks like Scion or counter focused decks like Ghave. She is pretty good just as a beatstick but without protection of any kind finishing the job with her is going to be hard.

Silumgar, Drifting Death-
I like just about everything about this card. The art, the flavor text, all of it is awesome. He is expensive and doesn't kill players very fast, but he is really good at controlling the board, and the more triggers you get the harder it is to stop him. The hexproof and toughness make it very hard to get Sil to stop swinging, basically forcing your opponent to have 8 power in the air before you even have to do anything. I can see him having a deck built around him for the guy that wants to play a more traditional U/B control list with lots of instants and a few cool dragon finishers.

Aside:
That's it for the cards we've seen. I wanted to talk about this as I was writing out the card reviews, but it seemed more appropriate for the end. They are trying to build a mono-color multicolor set.You'll notice how many of the cards I listed in multicolor that are only there because of the color identity rules for edh, but whose actual mana cost is one color. All of the legends, the mythic cycle of hybrid mana cards, and so forth. I decided not to put the uncommon cycle in multicolor because you can play them in mono-color even if they would be just vanilla. They tried to build this set in such a way that you can pick one color in limited and just play basics of that color and be fine, but if you do play some of another color that'll only help you. That's because FRF is attached to the wedge set. They want you to be able to keep your options open in limited and not get screwed over by color, but still have cards that have more complex and open constructed applications. You can be in R/x in your first booster and then transition in Mardu or Temur in KTK. In standard or limited, you can easily play Brutal Hordechief in mono-B, B/W, B/R, or Mardu, but in EDH you can only play it in Mardu. So while the way these cards are cost in every other format makes them more open, the costs make the cards more limited in EDH. This is the essential paradox of the color identity rule.

Hybrid mana was designed specifically as an either or state of mana, making the cards more open and easier to play. Color identity sees hybrid as an "and" state instead of an "or" state thus limiting the application of the cards. I really dislike the rules committees ruling on hybrid mana because it is exactly the opposite as the intention of the cards that have hybrid mana. If there had only been Ravnica then Shadowmoor, maybe it wouldn't be as much of an issue to me, but as the spoiling of Yasova Dragonclaw proves, they consider Hybrid mana to be evergreen and will use it wherever they think it fits into the design of the set. Hybrid isn't going to be some corner case in the future but an ever growing portion of the card base. I don't know why they made the decision they did, but I imagine it has to do with complexity. That handling hybrid mana differently would require a significant rules update and that people buying into the format would have to figure out more than they consider fair, that magic is a complicated enough game and that they want EDH to be as close to real magic as possible. I give the people that play magic more credit and think that tweaking hybrid to work as the designers intended is a noble, attainable, and non-catastrophic goal.

This isn't the first time that people have had to present good arguments to get them to change their mind. Memnarch, Bosh, and other generals used to be useless since color identity didn't take into account the text box of the card in question. While hybrid mana won't ruin EDH and the gains of changing the rules right now would be relatively minor, its something that is going to come up over and over as they print more hybrid cards. I'm certain I'm not the only person that thinks that the hybrid rules are restrictive and against the spirit of the cards it appears on. I'd love to play Debtor's Knell in Mimeoplasm or Brutal Hordchief in Oloro, and those are just the first two that come to mind. I'm not sure how I'd reword the rule. Maybe since its supposed to be either or you'd have to pick one color beforehand? It would need some testing to sus out what felt right, but the current iteration has been out lived.