I don't normally go through the entire spoilers but some interesting stuff.. With some things already said lets look at a few cards.
Urza's Ruinous Blast is a crazy board wipe especially in EDH
Benalish Marshal is a good card but casting for 3 white is very tough and specific making it harder to cast in multicolor decks.
Haphazard Bombardment ummm ok so eventually you destroy 3 permanents for 6 mana and you only destroy 1 during your end step. So dropping this on turn 6 to possibly destroy 3 permanents with aim counters on them by the end of turn 8? However it does carry that merit of destroying some ones best creature right off the bat. It could become more usefull if it is blinked or copied.
Settle the Score at sorcery speed and an uncommon it is a really good card.
Exile target creature and put 2 loyalty counters on a planeswalker. You can't ask for much more for a 4 drop
Whisper, Blood Liturgist an uncommon commander with recursion that you can have fun with. If not one heck of a sac outlet for Meren.
Tap, Sacrifice two creatures: Return target creature card from your graveyard to the battlefield.
Gruun, the Lonely King and give this thing trample along with kicking it and you will have a massive beater swinging for 20. Somehow play this and toss
rancor on it makes it 24 trample damage instead.. High casting cost but boy what a beater
4 GG (4 colorless and 2 green)
Legendary Creature - Ape Warrior
Kicker 3 (You may pay an additional 3 as you cast this spell.)
If Gruun, the Lonely King was kicked, it enters the battlefield with five +1/+1 counters on it.
Whenever Gruun attacks alone, double its power and toughness until end of turn.
Deep Freeze this for 3 mana to turn any creature into a 0/4 wall that loses all abilities is specific but boy it will take care of that beater previously mentioned
Sylvan Awakening can make an all out attack on your opponent. All lands you control become 2/2
Elemental creatures with reach, indestructible, and haste. They're still lands.
Fall of the Thran Oh boy land destruction.. (As this Saga enters and after your draw step, add a lore counter. Sacrifice afters III.)
I - Destroy all lands.
II, III - Each player returns two land cards from their graveyard to the battlefield.
Granted you get to return up to 4 lands but destroying mana bases is definitely
BOOM!
Damping Sphere is insane because of the ability If a land is tapped for two or more mana, it produces ◊ instead of any other type and amount.
Each spell a player casts costs 1 more to cast for each other spell that player has cast this turn. Only cost 2 colorless and its an artifact. Nuts I say
Forebear's Blade is nuts to, long as attacking creature dies you get to equip it to another creature or should I say attach it for free. It is 3 to cast
Artifact - Equipment
Equipped creature gets +3/+0 and has
vigilance and trample.
Whenever equipped creature dies, attach
Forebear's Blade to target creature you control.
Equip 3
I won't speak much on the legendary creatures and stuff, the gold border ones but this set is to me anyway very powerful in lots of ways