I don’t really know what to do here. I guess I want scrying to help with Keranos’s trigger, but how much of it do I want? Its probably safe to put quite a few into the mix, because they will be highly contested, efficient cards.
Keranos’s Two-Colored Cards
Sadly, there aren’t many UR cards that scry (well, two). I’ll just put random goodstuff here, then.
Stormcaller of Keranos gets in for flavor reasons.
Stormchaser Chimera is probably tied into Keranos somehow as well.
Quicksilver Dagger might be too good, depending on how much removal there is in the set, but its definitely an aura that’s worth its cost.
Spellbound Dragon seems like a fun effect. Never played it though.
Aqueous Form is a nice card with quite a few big creatures, but its also the cheap and somewhat reliable way to get ongoing scry triggers.
Eyes of the Watcher is another ongoing source of scrying.
I’ve always liked Fated Infatuation, even though I haven’t been able to use to effectively that often because of the heavy blue requirement. Despite this, its a good trick, which people don’t expect.
Mystic Speculation is another source of scrying and with enough mana, it can be very good with some of the red cards below.
Omenspeaker is just a cheap, efficient blocker with an upside.
Even Keranos needs bodies, so Prescient Chimera.
Divination is in just because the Theros-version (or Born of the Gods, to be precise) is Keranos-flavored. Its still pretty good, but probably not good enough for the cube longterm. It is also a sorcery, which is nice with some cards on this list, keeping this from being strictly worse than, say, Mulldrifter.
Because just scrying would be boring, here’s a card that can benefit from those in a nice way: Flamespeaker Adept.
Here’s another: Knowledge and Power.
Magma Jet is good removal with scry. No question here.
Sigiled Skink isn’t quite good as you’d need for the cube, but its okay.
The cube is lacking in tricks, so maybe Titan’s Strength.
Brutal Deceiver doesn’t quite scry, but is more efficient, if you can scry often.
Galvanoth gives you an edge for being able to scry. Getting even one spell off is pretty good, getting two spells is really good.
Goblin Spy is pretty poor, but seems like fun. At least it tells you when to use that scry-effect.