msem-instigator

Whenever you sacrifice a permanent, you may put a soul counter on Soul's Guidestone.
As long as there are five or more soul counters on Soul's Guidestone, it's a 6/6 Golem artifact creature with menace and vigilance.

{1}, {T}, Sacrifice Soul-Synthesizer: Look at the top seven cards of your library. You may reveal a card with an activated ability from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Activated abilities of cards in your graveyard cost {2} less to activate.

Activated abilities of cards in your hand cost up to {1} less to activate. This effect can't reduce the amount of mana an ability costs to activate to less than one mana.

{3}, {T}, Sacrifice a non-Spirit creature: Create a 1/1 white Spirit creature token with flying.

Whenever you cast a noncreature spell, you may put a progress counter on Sovereign Skies.
[PROGRESS 2+] Indestructible
{T}: Add {C}.
[PROGRESS 9+] Sovereign Skies is a 9/9 Ship artifact creature with flying.

{1}, Sacrifice Sovereign Stone: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{1}, Sacrifice Sovereign Stone: Draw a card.

Equipped creature gets +3/+1 and has reach.
Equip {4}

Spare Supplies enters tapped.
When Spare Supplies enters, draw a card.
{2}, {T}, Sacrifice Spare Supplies: Draw a card.

{T}: Add {C}.
{T}: Add one mana of any color among planeswalkers you control.
{1}, {T}: Put a loyalty counter on target planeswalker that activated a loyalty ability this turn.

{2}: Sparkline Dancer gains flying until end of turn.

Sparring Ground enters with a +1/+1 counter on it.
{T}: Add {C}.
Whenever a creature you control enters, you may move a +1/+1 counter from Sparring Ground onto that creature.

When Specialized Training Dummy enters, choose a card name.
Other creatures you control with the chosen name get +1/+1.

Flying
Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{5}: Each opponent sacrifices a nonland permanent.

When Spellblade enters, you may exile an instant card with mana value 2 or less from your hand.
At the beginning of your end step, if equipped creature dealt damage to an opponent this turn, you may copy the exiled card. If you do, you may cast the copy without paying its mana cost.
Equip {2}

When Spellbound Gauntlet enters, put a +1/+1 counter on target creature you control.
{T}: Add one mana of any color.

When Spellslinger's Gauntlet enters, exile an instant or sorcery card with mana value 3 or less from your hand.
Whenever equipped creature attacks, you may copy the exiled card. If you do, you may cast the copy without paying its mana cost.
Equip {3}

Defender, flying
Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)
Remove a +1/+1 counter from Spellwork Bulwark: It loses defender and gains hexproof and indestructible until end of turn.

{1}, {T}, Exile Sphere of Sorcery: Return target noncreature, nonland card from your graveyard to your hand.
{8}, {T}, Exile Sphere of Sorcery: Return any number of target noncreature, nonland cards from your graveyard to your hand.

When Spinegraft Disabler enters, exile target creature until Spinegraft Disabler leaves the battlefield.

Haste
Ward—Sacrifice a creature.
Spinning Gears Abomination enters with X +1/+1 counters on it.
Spinning Gears Abomination can't attack alone.

{T}: Add {C}.
{T}: Add one mana of any color among creatures you control.
{X}: Spirit Blossom Shrine becomes an X/X Spirit creature until end of turn. It's still a land. Activate only if you control a creature with power X.

Whenever you cast a noncreature spell, you gain 1 life.

When Splinter of Creation enters, you may exile any number of land cards from your graveyard.
You may play lands exiled with Splinter of Creation.

{T}: Add {C}.
{4}, {T}: Create a 0/1 white Goat creature token.
{T}, Sacrifice X Goats: Add X mana of any one color. You gain X life.