Yeesh. Clunky and narrow. The only way this card could be worse is if it didn't say "up to one target creature" and you couldn't play it if there were no creatures in play like with Suffocating Blast. Do we want a really hard to cast Essence Scatter with mild upside? This is a really bad Mystic Snake outside of Standard in most situations. This is likely a bulk rare. If you think about the spells a Temur deck wants to be countering, creatures aren't among them and they will likely look elsewhere.
"As discussed, here is one gem. Make sure the guy on guard duty falls asleep"
"ONE gem? Are you kidding me right now? You pour the whole bag out for the photograph but when it's my turn I get ONE gem? Cheapskate. I hope your dude gets blocked"
"What color wheel?"
High Sentinels of Arashin
I must break you.
This could easily have been a legendary creature, which would have allowed it to be an EDH general, which would have allowed me to build a bird tribal deck around it. I guess Derevi is a better bird tribal general anyway.
This guy seems really slow for Standard, but so do all of the creatures with morph. Evasion and a good mana sink make this an obvious busted first pick in limited, but we'll see if Standard games last long enough for you to scale out of control with this guy. I think he has potential and despite costing more, I think he is one of the better Abzan cards I've seen that put counters on things.
Retribution of the Ancients
I like this card a ton. It is a great way to kill utility guys that don't participate in combat and don't have "Caryatid" in their name, and 1 or 2 counters can throw off their combat math enough that you creatures win in combat - it may not be necessary to shrink one creature completely when the same investment of counters can doom a legion. This is a late-game card and you will likely have to invest a lot of mana to get those counters, but Hardened Scales can help with that. If Abzan is a thing, I can see this seeing play, but how much I can't say.
Solid reprint, unless you hate how oppressive black has been lately.
Just reprint Electrolyze. Why did you reprint not Electrolyze? Was Electrolyze broken? Black gets a Despise reprint, but Red/Blue gets a half-assed Electrolyze? WHY? WHY?
Dig Through Time
I have to imagine they tested this card with "put the rest in the graveyard" and it was too good. Or they didn't, who knows? Either way, I am not sure about this card. Drawing the best 2 in the top 7 is very good. How much mana do we want to pay? I am inclined to say Sultai Dredge will be a deck. I am inclined to say that this degree of card selection is very strong. I am not inclined to guess a price here, or even whether it will get played. In a vacuum, I don't like this a ton, but if that deck develops, this is a potential tool.