msem-instigator

When Sire of the Wild enters the battlefield, reveal the top four cards of your library. You may put a creature card from among them onto the battlefield. Shuffle the rest into your library.

Vision (Whenever this or another creature enters the battlefield under your control, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Spectral Hunter envisions a creature card, creatures you control get +1/+0 until end of turn.

When Stoic Observation enters the battlefield, mill two cards, then you may return a creature card from your graveyard to your hand.
{3}{G}, Exile a creature card from your graveyard: Create a 2/2 green Wolf creature token. You gain 2 life.

Indestructible
If Tarraka-no-Oni would be put into a graveyard from anywhere, reveal Tarraka-no-Oni and shuffle it into its owner's library instead.

Vision (Whenever this or another creature enters the battlefield under your control, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Tracker of Wild Places envisions a creature card, you may untap a permanent you control.

Enchant creature
Enchanted creature gets +2/+2 and has vigilance.
{2}{W}: Return Tranquil Endeavors from your graveyard to your hand.

Create four 3/3 green Elemental creature tokens.
Flashback {7}{G}{G}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Reveal the top thirteen cards of your library. For each permanent type, you may put a card of that type revealed this way into your hand. Put the rest into your graveyard. (The permanent types are creature, land, artifact, enchantment and planeswalker.)

When Weald Sentry enters the battlefield, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
When Weald Sentry dies, draw a card.

Search your library for up to two basic land cards and put them onto the battlefield tapped, then shuffle.
Fuse (You may cast one or both halves of this card from your hand.)

Create a number of 3/3 green Elemental creature tokens equal to the number of differently named lands you control.
Fuse (You may cast one or both halves of this card from your hand.)

Defender
Whenever you cast an instant or sorcery spell, you may untap Almgrove Sentinel.
{T}: Almgrove Sentinel deals 1 damage to any target.

Whenever a card is put into a graveyard from anywhere, put a +1/+1 counter on Chief Striking Dawn.
{1}{B}{G}, Remove three counters from Chief Striking Dawn: Return a permanent card from your graveyard to the battlefield.

Indestructible (Damage and effects that say “destroy” don't destroy this creature.)
Whenever Declare, the Mother Bear deals combat damage to a player, put a +1/+1 counter on it.

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.

You may play lands from your graveyard.
{B}{G}, Sacrifice three lands: Return Endrison Nourisher from your graveyard to your hand.

When Holy War enters the battlefield, create three 1/1 white Cleric creature tokens.
Creature tokens you control have first strike and lifelink.

Flying
Nonland permanents your opponents control enter the battlefield tapped.
Activated abilities of permanents your opponents control that entered the battlefield this turn can't be activated unless they're mana abilities.

When Keeper of the Whispers enters the battlefield, nourish 3. (To nourish 3, either put three +1/+1 counters on this creature or create three 1/1 white Citizen creature tokens.)
Sacrifice a creature: Creatures you control get +1/+1 until end of turn.

Target creature gets +X/+X and gains trample until end of turn, where X is the number of lands you control.
Fabled {4}{R}{G} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that creature.)

Equipped creature has indestructible as long as it's your turn.
Whenever equipped creature attacks, it gets +X/+0 until end of turn, where X is its power.
Equip {6}

If a player would lose life, that player loses 3 life instead.
If a player would gain life, that player gains 3 life instead.

Exile the top card of your library, a card from your hand and a card from your graveyard. Put one of the exiled cards on top of your library, one into your hand, and the other into your graveyard.

Vigilance, trample
{5}{R}{G}: Monstrosity 4. (If this creature isn't monstrous, put four +1/+1 counters on it and it becomes monstrous.)

Each instant and sorcery card in your graveyard has reprise. The reprise cost is equal to its mana cost. (As you cast an instant or sorcery spell, you may exile one card with reprise from your graveyard and pay its reprise cost. If you do, add its effects to that spell.)
Reprising spells you control can't be countered.