Nether's Gift
Enchantment
When ~ enters the battlefield, search your library for a card, exile it face down, and shuffle your library. You may look at that card at any time, and cast it as long as it's your opponent's turn.

Silent Spirit
Creature - Spirit
Flying, Flash
When ~ enters the battlefield, players can't cast spells this turn.
1/1
Her tombstone promised her that she could "rest in peace", a promise she had to enforce herself.

Nether Turbine
Artifact
: Put a charge counter on Nether Turbine. Then, add for each charge counter on Nether Turbine.

Storming Peasant
Creature - Human
Haste
Whenever an opponent casts a spell, if it wasn't the first spell cast this turn, ~ deals 1 damage to that player.
"I've had enough of the highborn living their lives of excess while we starve in squalor!"

And introducing a new ability word: privilege!

*privilege* - whenever this creature blocks or becomes blocked, (trigger).

Privilege is a keyword used to represent the declining aristocracy of Nichet. It can serve as simple Bushido, or perform more complex roles. Check it out:

Robber Baroness
Creature - Human Noble (C)
Privilege - whenever ~ blocks or becomes blocked, each opponent loses 2 life.
1/4

Tireless Researcher
Creature - Human Wizard Noble (U)
Privilege - whenever ~ blocks or becomes blocked, draw two cards and you lose 2 life.
2/2
He publishes til he perishes.

Familial Benefactor
Creature - Human Noble
Privilege - whenever ~ blocks or becomes blocked, put a +1/+1 counter on another target Noble creature you control.
2/1
"Everything I have I owe to my family, and I shall use everything I have to give back to them."

Adventurous Youth
Creature - Human Noble (C)
Privilege - whenever ~ blocks or becomes blocked, it gets +2/+2 until end of turn.
2/2
In times past, highborn youths would need to seek out or create their own perils to sate their lust for adventure. No longer.

Lord of the Manor (U)
Creature - Human Noble
Privilege - whenever ~ blocks or becomes blocked, Noble creatures you control get +1/+1 until end of turn.
2/2
"My family line has persisted unbroken for thousands of years. I will not be the one who allows it to fall."

Wisened Hunter
Creature - Human Scout Noble (C)
Privilege - whenever ~ blocks or becomes blocked, put a +1/+1 counter on it.
2/4
"What doesn't kill you makes you stronger. Or costs you a finger."

Topiary Tender
Creature - Human Noble (U)
Privilege - whenever ~ blocks or becomes blocked, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle your library.
1/3

But what good is a mechanic without enablers? No good at all, that's what! Here, take some:

Riposte
Instant (C)
Untap target creature. It gains protection from the color of your choice until end of turn.
Parry and turnabout, in one single, fluid motion.

Pheasant Fetchers
Creature - Hound (C)
When ~ enters the battlefield, draw a card the next time one or more creatures you control deal combat damage to a player this turn.
4/5

Dissatisfied Duelist
Creature - Human Noble (C)
When ~ enters the battlefield, target opponent must attack you with at least one creature during their next combat if able.
3/2
"You have insulted me, and my blade demands honor. Meet me at the castle fountain tomorrow at sunrise."
-Sealed Letter

Lowland Mists
Instant (C)
Prevent all combat damage that would be dealt this turn.
Draw a card.

Strength of Generations
Instant (C)
Target creature gets +3/+3 until end of turn. If that creature is a Noble, untap it.
"I learned to use a sword from my father, who learned from his mother, who learned from her mother before her. You will not best me."
-Alisir Concordat

Baraillon, the Crystal Palace
Legendary Artifact (M)
If a triggered ability you control would be triggered, it triggers twice instead. You may choose new targets for the copy.
The seat of opulence. The seat of power.

But of course, not everyone is content to allow the wealthy their privilege:

Blackpowder Anarchist
Creature - Human Rebel (R)
Whenever a triggered ability you don't control of a card, spell, or permanent is triggered for the first time each turn, ~ deals 2 damage to that ability's controller.
2/2
"The nobility, the emperor, the assembly, they all just want the power to crush the people underfoot. I'll burn them all down."

Balance Keeper
Creature - Human Rebel (R)
Whenever a triggered ability you don't control of a card, spell, or permanent is triggered for the first time each turn, counter that ability unless its controller pays .
2/2
"All are equal in worth, and all must be kept equal in stature."

engaging in creature combat doesn't evoke the word privilege to me

Anarchist and Keeper both draw the game off their own abilities.
peasant is cool

They get an advantage in creature combat. More importantly, I wanted to include this mechanic in those colors, and the faction for those colors is Nobles, so I gave them a nobility-related keyword.

I should fix those cards so they don't do that. Ditto for Baraillon. Good call.

Nestguard Roc
Creature - Bird
Flying
Whenever ~ blocks, it gets +2/+0 until end of turn.
1/3
"Roc eggs are the size of squibmelons. Each female lays only one per season, and will fight any intruder to the death to protect it."
-Almenia's expedition notes

Galeshaper
Creature - Elemental
At the beginning of each combat, target creature gains flying until end of turn.
2/6
Galeshapers find flight exhilarating and love to share the experience with humans, willing or otherwise.

Jenara's Champion
Creature - Human Knight (R)
Exalted
Whenever a creature you control attacks alone, it can't be blocked by more than one creature this turn.
3/3

Cantrip charms!

Arcanist's Charm
Instant
Choose one, then draw a card:
-Draw a card, then discard a card.
-Counter target spell unless its controller pays .
-Return target attacking creature to its owner's hand.

Necromancer's Charm
Instant
Choose one, then draw a card:
-Return target creature card from your graveyard to your hand.
-Target creature gets -1/-1 until end of turn.
-Exile all cards in target player's graveyard.

Sparkmage's Charm
Instant
Choose one, then draw a card:
-Exile the top card of your library. You may play it until the end of your next turn.
-~ deals 1 damage to target creature or player.
-Target creature gets +3/+0 until end of turn.

War Priest's Charm
Instant
Choose one, then draw a card:
-Target creature gains protection from the color of your choice until end of turn.
-Tap up to two target creatures.
-Create a 1/1 white bird creature token with flying.

Druid's Charm
Instant
Choose one, then draw a card:
-Put a +1/+1 counter on target creature.
-Search your library for a basic land card, reveal it, put it into your hand, then shuffle your library.
-Target creature blocks this turn if able.

I would word these:


Many of these modes read fairly weak (even considering the cantrip and flexibility). If I designed these, I'd make one "obvious" choice and two situational ones that function on different axes.

I think you underestimate the value of drawing a card, and of situational modes. This is as far as I feel comfortable pushing them.

Mitosis
Tribal Sorcery - Ooze
As an additional cost to cast ~, sacrifice a creature.
Create two tokens that are copies of the sacrificed creature.

Inspired by Mata: viewtopic.php?f=17&t=26095

Abyssal Tutor
Sorcery
Search your library for a card, put it into your hand, then shuffle your library. If you cast ~ from your graveyard, put that card into your graveyard instead.
Flashback

Versatility!

Plague Upon
Instant
Choose a permanent type. Target player sacrifices a permanent of the chosen type.

Raid or Plunder
Sorcery
Choose one -
-Raid or Plunder deals 2 damage to any target
-Destroy target artifact with converted mana cost 2 or less.

Truth or Consequences
Sorcery
Choose one -
-Target player discards a card
-Destroy target creature with toughness 2 or less.

Triumph or Downfall
Instant
Choose one -
-Target creature gets +2/+2 until end of turn
-Triumph or Downfall deals 2 damage to target creature with flying.

Let's get some enemy color commands going:

Savra's Command
Instant
Choose two -
-Destroy target nonland permanent with converted mana cost 1 or less.
-Put the top 5 cards of your library into your graveyard.
-Each player sacrifices a creature.
-Return up to one creature card from your graveyard to your hand.

Momir's Command
Instant
Choose two -
-Search your library for a basic land card, put it into your hand, then shuffle your library..
-Target creature gets +2/+2 until end of turn.
-Return target creature to its owner's hand.
-Draw a card.

Niv-Mizzet's Command
Instant
Choose two -
-Counter target spell unless its controller pays .
-Niv-Mizzet's command deals 2 damage divided as you choose between any number of targets.
-Put a card from your hand on the bottom of your library. If you do, draw two cards.
-Copy target instant or sorcery spell with converted mana cost 3 or less. You may choose new targets for the copy.

Razia's Command
Instant
Choose two -
-Create a 2/2 White Knight creature token with vigilance.
-Creature you control get +2/+0 until end of turn.
-Creatures you control get +0/+2 until end of turn.
-Destroy target artifact or enchantment.

Obzedat's Command
Instant
Choose two -
-Return target creature card with converted mana cost 3 or less from your graveyard to the battlefield.
-Target creature's base toughness because 1 until end of turn.
-Creatures you control gain protection from target spell or permanent until end of turn.
-Creatures you control gain lifelink until end of turn.

Prismatic Charm
Instant
If was spend to cast ~, target creature gets +1/+2 until end of turn.
If was spent to cast ~, return target tapped creature to its owner's hand.
If was spent to cast ~, return target creature card from your graveyard to your hand.
If was spent to cast ~, ~ deals 1 damage to any target.
If was spent to cast ~, search your library for a basic land card and reveal it, put it into your hand, then shuffle your library.

Villify
Enchantment - Aura
Enchant creature
Enchanted creature gets -2/-2 and isn't a human.

Completing the Archmage's Charm cycle:

Archfiend's Charm
Instant
Choose one:
-Destroy target creature.
-Creatures get -2/-2 until end of turn.
-Return up to two target creature cards from your graveyard to your hand.

Archdruid's Charm
Instant
Choose one:
-Create a 3/3 green Beast creature token.
-Search your library for a land card, put it onto the battlefield, then shuffle your library.
-Put a +1/+1 counter on target creature you control. It deals damage equal to its power to another target creature.

Archangel's Charm
Instant
Choose one:
-Exile target artifact or enchantment.
-Destroy all creatures with power 4 or greater.
-Permanents you control gain protection from the color of your choice until end of turn.

Anarchist's Charm
Instant
Choose one:
-Anarchist's Charm deals 3 damage to any target.
-Untap target creature and gain control of it until end of turn. It gains haste.
-You may choose new targets for target spell or ability.

White should get "You gain 4 life" instead of "Destroy all creatures with power 4 or greater."

Retribution of the Meek is a sorcery.
Divination is a sorcery.
If Archmage's Charm can do the latter, what's wrong with this charm doing the former? is a pretty steep cost, and modern is a pretty pushed format. If this card was printed in modern horizons, it's pretty likely that it wouldn't see any modern play as is.

Oh, I was just making a comment about how white normally gets a bad lifegain mode in place of something strong and useful like Retribution of the Meek.
It wasn't a serious gesture.

Fertilize
Instant
Counter target spell. Search your library for a basic land card, put it onto the battlefield tapped, then shuffle your library.
"Our magic draws power from the land, and to the land it shall return."
-Aysa, Juniper Order Druid