msem-instigator

Create two 1/1 white Soldier creature tokens. Prevent all damage that would be dealt to them this turn.

{T}: Add {C}.
Whenever Mustering Grounds becomes tapped, if it's enchanted, you may pay {2}. If you do, create a 1/1 white Soldier creature token with vigilance.

Whenever a creature you control dies, destroy target creature you don't control.

Menace
Other attacking Hounds you control get +2/+0.

Reveal cards from the top of your library until you reveal a creature card and a land card. Put those cards into your hand and the rest on the bottom of your library in a random order.
Concord — If there are four or more card types among permanents you control, create two Treasure tokens.

Whenever Mysteries of Life enters or you create a token, choose one that hasn't been chosen this turn —
• You gain 2 life.
• Draw a card, then discard a card.
• You may tap or untap target permanent.

Whenever a card is put into a graveyard this turn, you may put it on the bottom of its owner's library.
Draw a card.

Return a permanent you control to its owner's hand.
Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Choose one —
• Return target artifact or enchantment card from your graveyard to your hand.
• Return target creature card with mana value 2 or less from your graveyard to your hand.
Cycling {2} ({2}, Discard this card: Draw a card.)

{T}: Add {C}. Spend this mana only to cast a creature spell with a creature type no creature you control has.

(As you complete a condition, decode it. After all are decoded, you solve the mystery and transform it.)
When Mystery of the Dying Herds enters, create a 0/2 white Ox creature token.
A creature you control dies.
You have 4 or more life than your starting life total.

{T}: Add one mana of any color. If that mana is spent on a legendary creature spell, it enters with an additional +1/+1 counter on it.

Create a token that's a copy of target creature, except its power and toughness are switched. Sacrifice that token at the beginning of your next end step.

Equipped creature gets +1/+1.
Equip {1}

When Mystic Mackerel enters, you may have target player mill two cards.
{3}{U}, Sacrifice Mystic Mackerel: Return target enchantment, instant, or sorcery card from your graveyard to your hand.

When Mystic Seer enters, each player may scry 1.
{2}{U}: Draw a card, then discard a card.

Whenever a player casts a spell, that player exiles the top card of each library face down.
Each player may look at and play cards they exiled with Mystic of Many Winds.

Enchant creature
When Mystic's Mantle enters, draw a card.
Enchanted creature gets +1/+1.
Mirage {G} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Each player mills three cards. For each instant and/or sorcery card milled this way, draw a card.

Reverberate {2}{G} (When you cast this spell, copy it if you paid its reverberate cost. The copy becomes a permanent when it resolves.)
Mystical Echo gets +1/+1 for each other Reflection you control.
Whenever you discard a card, Reflections you control gain trample until end of turn.

{T}: Mystical Elk becomes a copy of target creature card in your graveyard. Activate only as a sorcery. (It loses this ability.)

{T}: Add {C}.
{3}, {T}, Sacrifice Mystical Tomb: Return target artifact, enchantment, or legendary card from your graveyard to your hand.

When Mythos Scribe enters, you may return target storied card from your graveyard to your hand. (Enchantments and legendary permanents are storied.)

[+1]: Reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.
[0]: You gain 1 life for each card in your hand.
[–7]: Search your library for up to X cards, where X is the number of cards in your hand, and put them into your hand. Then shuffle.

You draw X cards and you lose X life, where X is the number of cards in your graveyard.