msem-instigator

If you would harmonize while this spell is on the stack, you may instead put three thunder counters on this spell.
Lightning and Thunder deals X damage to any target, where X is 3 plus the number of thunder counters on Lightning and Thunder.

Reveal the top five cards of your library. Put a creature or enchantment card from among them into your hand. Put the rest on the bottom of your library in a random order.

Living Broadcast can't block.
Whenever you cast a spell from exile, you may return Living Broadcast from your graveyard to your hand.

Each other creature you control that's an Elf or a Warrior gets +1/+1.
{2}, Sacrifice Llanowar Exemplar: Creatures you control gain indestructible until end of turn.

Counter target spell unless its controller pays {1}. If you control a creature with flying, counter that spell unless its controller pays {4} instead.

Transcend (Activate as a sorcery to gain the next type and a +1/+1 counter.)
Lifelink
Demon spells you cast cost {B} less to cast and an additional 2 life to cast.
{3}{B/R}{B/R}: Demon
Discard your hand. Draw a number of cards equal to the greatest power among Demons you control.
{5}{U/B}{U/B}: Noble
Gain control of target creature. You lose life equal to its mana value.

When Loresprout enters, if you control another creature, draw a card.

Lost Station enters tapped.
{T}: Add {U}.
{U}{U}: Until end of turn, Lost Station becomes a 2/2 Horror creature with “This creature can't be blocked.” Activate only if you're horrific.

Creatures can't attack you or planeswalkers you control unless their controller pays 2 life for each of those creatures.

Changeling (This card is every creature type.)
{1}: Another target creature you control gains the creature type of your choice until end of turn.
{1}: Change the text of another target creature you control by replacing all instances of one creature type with the creature type of your choice until end of turn.

When you cast this spell, copy it for each color of mana spent to cast it beyond the first.
Flying

Players can't sacrifice creatures to cast spells or activate abilities unless that player sacrifices an additional creature. The same is true for discarding cards and paying life.

Creatures you control get +2/+2.
Wanderlust — As long as you control four or more differently named lands, creatures you control have trample and can't be blocked by more than one creature.

(Choose only one work as a sorcery to add its abilities.)
When Make Art Not Friends enters, create a Treasure token.
{1}{R}: Never Again
Whenever you sacrifice an artifact, that artifact deals 1 damage to each opponent.
{4}{R}{R}: Over It All
At the beginning of combat on your turn, you may have an artifact you control become a 6/6 Golem artifact creature until end of turn.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Whenever Manipulator of Waves attacks, mill three cards. Then create a 0/0 blue Elemental Serpent creature token with “This creature gets +1/+1 for each five cards in your graveyard.”

Whenever Maritime Thug becomes tapped, it deals 1 damage to each opponent.

When Master of the Abyss enters, draw two cards, then discard a card.
{2}{U}{U}, {T}, Discard two cards: Create an X/X black Horror creature token, where X is the number of cards in your graveyard.

Equipment spells you cast cost {1} less to cast.
Equip abilities you activate cost {1} less.

When Maven of Fear enters, mill two cards.
Maven of Fear gets +2/+1 and has menace as long as six or more cards are in your graveyard.

Reach
When Mawdryk's Harrier enters, look at the top six cards of your library. You may put an Elf card with lesser mana value from among them onto the battlefield. Put the rest on the bottom of your library in a random order.
Other Elves you control get +1/+1.

Whenever you gain life, Militant Youth gets +1/+1 until end of turn.

Other creatures you control get +2/+0 and have menace.
Whenever another creature you control dies, if it wasn't sacrificed, sacrifice a creature.

Misty Churchyard enters tapped.
{T}: Add {W}.
{1}{W}{W}: Until end of turn, Misty Churchyard becomes a 1/4 Cleric creature with “Whenever this creature is dealt damage, put that many +1/+1 counters on it.” Activate only if you're horrific.

Dragon spells you cast cost {1} less to cast.
{1}{R}: Until end of turn, Miyoga Dragonsoul becomes a 2/2 red Dragon creature with flying and “{R}: Miyoga Dragonsoul gets +1/+0 until end of turn.” Activate only as a sorcery.

Target creature you control gains indestructible until end of turn if it has a +1/+1 counter on it. Then it fights target creature you don't control.