Binding Intervention
 
Instant
As an additional cost to play Binding Intervention, remove two lands you control and two
cards in your hand from the game.
Split Second
Until end of turn, target player can't play spells or activated abilities. Tap all permanents that player controls. You may counter target spell, activated ability, or triggered ability.


I really liked the white counterspells in Planar Chaos. Makes sense to me.
White, I think, as it expands its color pie abilities, is well placed to play around with losing resources, card disadvantage and tempo as a cost for expanded powers. Split second / uncounterability works well with the really big ones like this, so that the overinvestment won't lose you the game. To me, everything makes sense in context. I don't think you put these kind of things on commons, but for rares definitely there's room for it. Cards that you invest a lot of resources into and that very reliably do something you want or stop something you don't want seem very White. White could be thought of like the DCI - the color that can bring down the hammer and use an emergency ban.

Inquisitor's Will
1WW
Sorcery
Kicker 2W
Destroy target permanent. If a land or creature was destroyed this way and the kicker cost wasn't paid, its controller may search his or her library for a card, put it into their hand, then shuffle their library. If an artifact or enchantment was destroyed this way and the kicker cost was paid, you gain 4 life and draw a card.

I think this is interesting, but is overpowered? I feel like each of the modes it could be cast for you is pretty fair, but is it all in one card just too good? I do think it's cool and one of the best cards I've designed, and I'm definitely a fan of white just basically having limited vindicating powers. It's also kind of cool that white can have a diabolic intent incidentally in the same card.

I'd love to see these at uncommon, and I think they are a great idea. We have the almost the entire weight of precedent for multilands on the side of rare, except for one thing -- the power level of this specific cycle. These are significantly worse than a lot of other manafixers because they do get your opponent a land. I'd say they are almost exactly on par with the Invasion taplands, which were indeed uncommon. I also agree with choosing an opponent, not each opponent. No reason to make the cards worse.

Out of everything there, I think Damping Quill is interesting, and I like the idea. But it's very narrow and underpowered.
I'd make it as:

Damping Quill [2]
Artifact
When Damping Quill comes into play, sacrifice an artifact and choose a card type other than land.
Spells of the chosen type cost [2] more to play.

Imprison and Exile
2WW
Enchantment - Aura
Enchant permanent
Enchanted permanent can't attack or block, its activated abilities can't be played, and its triggered abilities don't trigger.
4WW: Remove enchanted permanent from the game and put Imprison and Exile on top of its owner's library.

I like this top-down flavor of white dealing with annoying permanents. I'm not sure about the triggered abilities part though. Has that ever been done, and could it be worded that way?

Abyssal Reaper
2BB
Creature - Spirit
Flying
When Abyssal Reaper comes into play, target player loses 4 life and target creature gets -4/-4 until end of turn.
When Abyssal Reaper leaves play, you lose 4 life.
At the beginning of your upkeep, you lose 4 life and sacrifice an artifact, creature, or land.
4/4

I thought this was an interesting symmetrical idea. Note how it can come into play and kill itself to make each player just lose 4 life for 2BB.
It's very suicidal and very aggressive, like the black creatures of Tempest/Urza's era design. When I think "black creatures that are awesome" I think of that flavor and those specific creatures.

I think an exact Swords to Plowshares reprint could be done for 1WW. White's been getting better at proactively dealing with non-attacking or blocking creatures lately. (Exactly the direction they moved a million miles away from after taking Swords out of the picture.)

Looking at it again, maybe Flash on top of everything is a bit much. I guess it wouldn't be fun to have U/W casting this at end of turn and sitting back on counters. That change I'll make.

I think it would be fine... those are limited power curves you're talking about. And yes, they are exactly accurate. I took my cue in part for this card also from Calciderm. Yes, it was a planeshifted Blastoderm. Yes, that set was supposed to bend the color pie. But I think what comes out of that are revelations of possible permanent changes as well as the 'what if'. That card filled a spot on white's curve that has usually been terrible in constructed. What we're getting into here, I think, is that I think white and green, creature power curves need to be adjusted to have the same spikes in power level, but less extreme. Green should have better at 1 and 2 and white should have better at 3 and 4. Green doesn't get Savannah Lion, but I think it should have its Pouncing Jaguars, Basking Rootwallas, and Albino Trolls. And white should not have a complete blank hole between bears and dragons/angels.
Just my two cents.

Angelic Vanguard
2WW
Creature - Angel Warrior
Flying, Vigilance
4WW: Angelic Vanguard gains first strike until end of turn.
4/3

Serra Angel which used to be the stones is now outdated for sure... I'd like to see a take on it done like this though.
Edit: Removed Flash.

Burning Wish is definitely a card whose tutoring power at 1R will never, ever be replicated.