msem-instigator

Rhapsody {4}{R}{R} (Pay {4}{R}{R} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
Trample
Whenever Attuned Slayer deals combat damage to a player, exile that many cards from the top of your library. You may play those cards this turn.

Haste
Augmented — At the beginning of combat on your turn, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, gain control of target nonland permanent until end of turn. Untap it. It gains haste until end of turn.

Flying
Other creatures you control with flying get +1/+1.

Autumnal Boscage enters tapped unless you control a basic land.
{T}: Add {R} or {G}.

Exile target creature or planeswalker. You gain 4 life.

First strike
Whenever you scry, Battlewise Paragon gets +1/+1 until end of turn for each card you looked at while scrying this way.

Augmented — When Behavioral Specialist enters, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, create a 1/1 blue Elemental creature token with flying.
Whenever one or more creatures you control deal combat damage to an opponent, you may draw a card. If you do, discard a card.

Enchant creature
Enchanted creature gets +1/+1 and has vigilance.
{2}{G}: Return Behold the Horizon from your graveyard to your hand.

Choose one —
• Target creature gets +2/+0 and gains first strike until end of turn.
• Destroy target artifact.

Return all creature and planeswalker cards from your graveyard to the battlefield.

{T}: Add one mana of any color a basic land you control could produce.

Return up to one target spell to its owner's hand.
Create two 1/1 blue Elemental creature tokens with flying. They can't block this turn.

When Bioluminescent Predator dies, draw a card, then you may put a land card from your hand onto the battlefield.

When Bizarre Dreams enters, destroy up to one target artifact or enchantment.
{3}{W}, Sacrifice Bizarre Dreams: Create two 1/1 blue Elemental creature tokens with flying. They can't block this turn.

Distribute three +1/+1 counters among one, two, or three target creatures you control.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Target creature you control gets +1/+0 until end of turn.
[Lore III] Target creature you control gets +2/+0 until end of turn.

If casting this spell causes a triggered ability of its target to trigger, that ability triggers an additional time.
Target creature gains first strike until end of turn.

When Brand New Species enters, create a tapped 3/2 green Horror creature token.
Augmented — At the beginning of each end step, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on up to one target Horror you control.

Whenever you attack or cast a multicolored spell, put a +1/+1 counter on Brandy Axel.
If Brandy Axel would be destroyed, remove a +1/+1 counter from her. If you do, instead remove all damage from her and she deals 2 damage to each opponent.

Enchant creature you control
When Brawnsurge enters, enchanted creature deals damage equal to its power to up to one target creature an opponent controls.
Enchanted creature gets +1/+1 and has trample.

Flash
When Brightsouled Guardian enters, return up to one target nonland permanent to its owner's hand.

Augmented — Whenever Bril, the Oltenen Emissary enters or attacks, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, destroy target permanent.

Create a 3/2 green Horror creature token.
Reconstruct {4}{G} (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.)

{T}: Add {C}.
{T}, Sacrifice Cave of Pleonexia: Destroy target nonbasic land an opponent controls. You and that player each create a Treasure token. Activate only as a sorcery and only if that land's controller controls four or more lands. (A Treasure token is an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Your opponents skip their upkeep steps.
At the beginning of your first upkeep each turn, you get an additional upkeep step after this step.