Spoiler season is the best season of all. We got a bunch of goodies to unwrap over the weekend, so let's get into trouble.

Dragonlord Silumgar

Are all of the two-color dragons from the last set returning as Elder Dragons? Just a few who are integral to the plot? It's hard to know, but what we do know is that this Silumgar has different abilities and I really like this one for EDH. I don't think we want to pay 6 mana for a Control Magic that dies to Valorous Stance but it's certainly a brutal play if you get it to stick. We underestimated the (very limited) standard playability of the last Silumgar, so maybe a control deck can emerge that can afford to pay this much to swipe a dude. What I do know is that I like this effect in EDH where you have more sac outlets and are less likely to have to give the creature back if they kill Silumgar. Even at mythic, it's hard to see this being a great preorder. That said, I can certainly envision a scenario where a control deck emerges that wants one or two of these out of the board to steal a planeswalker or dude from a deck that can't reasonably kill Silumgar to get them back. Still, you're relying on their deck a bit. If this does become a control finisher, that limits its upside a bit compared to cards that are non-sideboard cards and get played as four-ofs. I'm burning a lot of ink to say "I don't know" but this is most likely a "no thanks" on the preorder unless the meta shapes up a lot before the whole set is out and we see a home for it and it simultaneously preorders for cheaper than a mythic, legendary dragon is likely to.

Dragon Tempest

Really, really hard to say. Cards like Outpost Siege have gone a long way to dispel the notion that people won't want to devote a whole spot in their 75 to an enchantment that needs other cards to be good (the Khans ability on Siege may contribute heavily) and cards like Crucible of Fire have demonstrated the ability to hit $5. This is no Crucible of Fire and it is kind of narrow unless you're all-in on Dragons. Does EDH want this in a deck with cards like Utvara Hellkite which can spiral out of control? Maybe, but I don't see this being a $5 card any time soon. Pandemonium is almost always better unless you're way ahead or really need to ping creatures and that card sees almost no play. In standard, playing this one two with no Dragons for a while is a big tempo loss. I don't see it.

Profound Journey

This seems like it could be very, very good in the right deck. I have a sneaking suspicion that the right deck has 100 cards rather than 60. Still, this effect is very, very powerful, and getting to rebound is very saucy. If we get cheap rebound spells, I think Jeskai gets very good in the future and this was a good way to both show that they may try to slow the format down even more with slow, expensive, powerful cards. I like this spell, but I doubt there is money to be made.

Stratus Dancer

"megamorph" is a euphemism for "run out of ideas".

That said, any deck where you add extra counters to something could benefit. I hope we get some green megamorph guys with decent abilities. Maybe Hardened Scales has a shot at doing something. Don't buy Hardened Scales right now. I don't think it's as likely as other financiers I see tweeting seem to. Stratus Dancer is a very cool throwback to a card like Willbender that they will have to play around and you could bluff other Morph creatures making them think twice about instants and sorceries. I think this card is likely to be overrated and I don't see it being a good presale pickup unless its price doesn't reflect the hype I keep reading. We'll wait and see on this card, but it's really fun to have it in the set, at least.

Sidisi, Undead Vizier

Is this good enough for 60 card decks? I could see that. a 5 mana 4/6 deathtouch isn't terrible value and that big butt makes sure it doesn't merely trade in combat, where she's a monster. The exploit ability is pretty nutty. Saccing an expendable creature, or even one who has an ability that triggers when the creature dies, can be a fine price to pay to go through your deck and find what you need. I have a lot of hope for this card.

Get foils of this. This is an unfair EDH general that you can cast from the command zone again and again, tutoring each time. They won't want to kill it in combat because it will draw you another card. Monoblack is full of expendable creatures to sac and ways to bring them back. This card may rival Maralen the Mornsong as the go-to black combo enabler, although Maralen lets you play a deck with 85 swamps if you want to be that cheesy and this requires you to have an actual deck with creatures in it. Still, the search is one-sided and I can see this being a very good general. If foils are at a 2x multiplier when the set drops, just know that the multiplier should be more like 5x, although it may achieve that if the non-foil price ends up being too high and the bottom drops out of it. Still,  I think there is money to be made on foils. This card is very good.

Dragonlord's Reaper

5BB
Creature - Dragon
Flying

When Dragonlord's Reaper enters the battlefield, if you cast it from your hand and there are five or more other creatures on the battlefield, destroy all other creatures.

Saucy. 7 mana is a lot, but we're talking about a creature that casts Damnation and swings for 5. This card is expensive and slow, and can't really do much if you're playing a creature-light control deck and they're beating your face in with 3 dudes, so you can't lean on this the way you can a Damnation, so watch that. I think this may be initially overrated a bit. The caveat that you must cast it from your hand further narrows its utility in other formats.  I still think this is good, but probably not as good as everyone thinks it is at first blush. That said, it's a Dargon, and that confers certain upside, although with the glut of dragons lately, even casual players with all-dragon decks are having to make cuts.