The Heroes of Akros
Enchantment - Saga (R)
I - Look at the top six cards on your library. You may put a creature card with mana value 2 or less from among those cards onto the battlefield. Put the rest of the cards on the bottom of your library in random order.
II - Until your next turn, whenever a player casts a spell that targets one or more creatures they control, they put a shield counter on each of those creatures.
III - Destroy all creatures.

Burden of the Past
Legendary Enchantment (M)
Auras are Sagas with:
I: Enchanted creatures base power and toughness becomes 1/1 until end of turn.
II: You gain life equal to enchanted creatures mana value.
III: Exile enchanted creature.
Each of us a bookmark in the pages of history.

Overthink
Instant (C)
Draw two cards.
Cycling
Madness

Water Wheel
Artifact (U)
, : Target player mills a card for each Island you control.
, , Mill four cards: You get for each Island card you milled activating this ability.
Islandcycling

Djinn of Forgotten Dreams
Creature - Djinn (R)
Flying
, Exile an enchantment from your graveyard: Create a soultorch token and attach it to a creature you control. (A soultorch token is an aura with "Enchant Creature", "Enchanted creature has +1/+1.", and "Enchanted creature can only be blocked by creatures with power greater than the number of auras attached to this creature.")
5/5

Pelagic Nightmares

Enchantment - Terror
When Pelagic Nightmares enters the battlefield and at the beginning of your upkeep, increase your terror level ( ) by 1. When you do, you may reclaim your and us it to choose modes of Terrors you control. You may choose the same mode multiple times.
- At the beginning of your end step, each player mills a card.
- Creatures attacking you get -1/-0
- Whenever an opponent casts a spell, you may counter that spell. If you do, reduce your terror level by 1 and forsake an instance of this mode.

In my mind, every "Terror" enchantment would have the same ETB and a menu of choices. Your would ramp up faster the more you have but would also need to be shared among your options. To reclaim your , all terror modes you've chosen become unchosen.

Hostile Environment
Enchantment (C)
When this enchantment enters, target opponent discards a card.
Eerie — Whenever an enchantment you control enters or you fully unlock a Room, up to one target creature gains menace until end of turn.

Sink Into Asphalt

Instant {U}
Target creature gets -3/-3 until end of turn. If it's your main phase, also put three -1/-1 counters on it.

Lim-Dûl's Strike

Instant {M}
Kicker
Destroy target creature or planeswalker. If Lim-Dûl's Strike was kicked, transform Lim-Dûl's Strike and put it onto the battlefield as it resolves.
//
Lim-Dûl's Slave
Creature - Skeleton {M}
As Lim-Dûl's Slave enters the battlefield, exile a creature or planeswalker card from an opponent's graveyard.
Lim-Dûl's Slave has power and toughness equal to the exiled card's mana values. If the exiled card has any activated abilities, you may activate one of them once per turn, during your turn.
*/*

Desperate Scrambler
Creature — Goblin Rogue (C)
Whenever Desperate Survivor attacks or blocks, you may discard a card or sacrifice a permanent. If you do, draw a card and reveal it. Desperate Survivor gets +X/+0 until end of turn, where X is that card's mana value.
Goblins are rarely pulled into Duskmourn, for they are both too stupid to be afraid of death and very adept at surviving unlikely odds.
0/2

Varchild's Marauder

Creature - Human Warrior {U}
Whenever a creature dealt damage by Varchild's Marauder this turn dies, its controller creates a 1/1 red survivor creature token.
"Always let one go. The fear they spread is worth more than a corpse."
3/3

Varchild's Exiles
Creature - Human Warrior (R)
Varchild's Exiles costs you less to cast from exile.
If Varchild's Exiles enters from exile, destroy all survivors.
3/3
This time they weren't going to make the same mistake.

Pyramid of Flame
Sorcery (M)
Choose X targets. Pyramid of Flame deals 1 damage to the first choice, 2 damage to the second, 3 to the third, and so on.

Cradle Warden
Creature ─ Elemental (C)
Echo ─ Put a Forest card from your hand onto the battlefield.
2/3
Mother, wake / Command our lives
Our roots unbound / Leaves crown your head.

Copsestalker
Artifact Creature — Scarecrow Warlock (U)
Delirium — When this creature enters, create a 1/4 colorless Scarecrow artifact creature token if there are four or more card types among cards in your graveyard
Coven — When this creature enters, mill three cards then return up to one permanent card milled this way to your hand if you control three or more creatures with different powers.
4/1

Jotun Chronicler
Creature - Giant Advisor (R)
Ward - Put five cards from your graveyard on the bottom of your library
At the beginning of your upkeep, put a +1/+1 counter on Jotun Chronicler, then sacrifice it unless you return X cards from your graveyard to your hand, where X is the number of +1/+1 counters on Jotun Chronicler.
4/4

Vivien, Smaragdi Partisan
Legendary Creature — Human Ranger (M)
Reach
Whenever another creature you control dies, exile it with a spirit counter.
Whenever Vivien attacks, if you own three or more creature cards in exile with a soul counter, exile her and return her to the battlefield transformed. You may activate her loyalty abilities any time you could cast an instant
1/4

Vivien, Last of Skalla
Legendary Planeswalker — Vivien
: Create a token that's a copy of a creature card you own in exile with a spirit counter.
: Until end of turn, target creature you control gets +1/+1 for each creature card you own in exile with a spirit counter. If a creature card you own in exile with a spirit counter has flying, that creature gains flying until end of turn. The same is true for first strike, deathtouch, hexproof, lifelink, menace, reach, trample, vigilance, double strike, haste, and indestructible.
: Put each card you own in exile with a spirit counter onto the battlefield. They gain haste.

Simic Historian
Creature - Vedalken Whale Advisor (C)
: Adapt 1.
Whenever another creature you control enters, you may move a +1/+1 counter from this creature onto it.
"We may not be proud of our history, but that doesn't make it unimportant."
2/2

Simic Doctor
Creature - Centaur Shaman (U)
Vigilance
Any amount of damage removed from a creature you control causes a +1/+1 counter to be put on that creature.
"As good as new! I hope you enjoy the modifications."
2/4