msem-instigator

Whenever a creature enters the battlefield under your control, you may gain 1 life.
{3}{W}: Populate. (Create a token that's a copy of a creature token you control.)

Put a divinity counter on target creature. It gains “This creature has indestructible as long as it has divinity counter on it.” (This effect lasts indefinitely.)

Flying
Demons and Vampires you control get +1/+1 for each player that has lost life this turn.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
You can't lose the game and your opponents can't win the game.
I — Your life total becomes 1.
II — Double your life total.
III — Create an X/X white Avatar creature token with indestructible, where X is your life total.

{B}, Remove a time counter from a permanent you control: Target player loses 1 life.

Foretell {2}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
If this spell is foretold, you may cast it as though it had flash.
Create a token that's a copy of target creature you control.

Destroy target creature or planeswalker.
Fuse (You may cast one or both halves of this card from your hand.)

Doom deals 3 damage to any target and you gain 3 life.
Reconstruct {3}{B}{B} (You may cast this from your graveyard for its reconstruct cost reduced by the mana value of a permanent you sacrifice as you cast it this way. Then exile this.)
You may cast Doom from exile by paying {4}{B}{B}{B} rather than its mana cost. If you do, shuffle it into your library instead of putting it anywhere else as it resolves.

Flying, first strike, haste
Whenever Doombringer Dragon attacks, you may sacrifice another creature. If you do, Doombringer Dragon gets +3/+0 until end of turn.

Double strike, trample
Enchantment spells you cast cost {1} less to cast.
Whenever you put a lore counter on a Saga you control, Douglass, Star of the Show gets +1/+1 until end of turn.

Primal—Reappropriate green. (During your turn, you may cast this spell by exiling two green cards from your hand and/or graveyard instead of playing a land.)
When Dovon's Masterwork enters the battlefield, return target land card from your graveyard to the battlefield tapped.

{R}: Draconic Aspirant gets +1/-1 until end of turn.

Equipped creature gets +0/+4 and has vigilance and reach.
Equip {3}

Ferocious — If you control a creature with power 4 or greater, you may cast Dragon Grip as though it had flash. (You may cast it any time you could cast an instant.)
Enchant creature
Enchanted creature gets +2/+0 and has first strike.

Dominance — When Dragon Queen's Pupil enters the battlefield, put a +1/+1 counter on it if you control the creature with the greatest power or tied for the greatest power.

Spirited (When this creature enters the battlefield, you may activate one of its activated abilities without paying its cost.)
{3}{G}: Mill three cards. Target creature gets +X/+X and gains trample until end of turn, where X is the number of land cards in your graveyard.

Prowess
Whenever Dragon's Eye Spiritualist attacks, the next spell you cast this turn costs {1} less to cast.

As an additional cost to cast this spell, discard a card.
Draw two cards and create a Treasure token.

Trample
Art of war — At the beginning of your end step, if Dragon's Wake dealt damage to an opponent this turn, gain control of target land for as long as Dragon's Wake remains on the battlefield.
Tap three untapped creatures you control: Dragon's Wake becomes an artifact creature until end of turn.

Spirited (When this creature enters the battlefield, you may activate one of its activated abilities without paying its cost.)
{3}{R}: When target creature dies this turn, create a 2/2 red Dragon creature token with flying and “{R}: This creature gets +1/+0 until end of turn.”

Defender
A deck can have any number of cards named Dragonwall Fragment.
At the beginning of your upkeep, if you control twenty or more creatures named Dragonwall Fragment, you win the game.

Flash
When Dragonwall Samurai enters the battlefield, prevent all combat damage target creature would deal this turn.

Flying
Ride {3}{U} ({3}{U}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

Search your library for a basic land card and put that card onto the battlefield tapped, then shuffle.
Create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Exile any number of target creatures you control, then return those creatures to the battlefield under their owner's control.