msem-instigator

The first creature spell you cast each turn costs {2} less to cast.
At the beginning of your upkeep, return a creature you control to its owner's hand. If you do, you draw cards and gain life equal to its power.

Defender
When Glacial Buttress dies, tap each creature that dealt damage to it this turn. Those creatures don't untap during their controller's next untap step.

Prowess
Gusma's Emissary gets +1/+1 as long as you control a black or green permanent.

The Oltenen Emissary is all colors.
You may pay {W}{U}{B}{R}{G} rather than pay the mana cost for spells that you cast. When you do, you may cast spells without paying their mana costs until end of turn.

Equipped creature gets +2/+1.
Whenever a creature you control enters, you may have equipped creature gain your choice of flying, vigilance, first strike or trample until end of turn.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Whenever you cast a legendary spell, create a 1/1 white Human creature token.
{W}{U}{B}{R}{G}: Search your library for a legendary card, reveal it, put it into your hand, then shuffle. The next legendary spell you cast this turn costs {W}{U}{B}{R}{G} less to cast.

Shuffle your library, then exile the top two cards. Until end of turn, you may play one of those cards. Whenever you play a card exiled with Goddess' Whimsy this turn that doesn't share a card type with another card played this way, repeat that process.

Create two 1/1 colorless Servo artifact creature tokens.
Leitmotif (If you cast this spell from your hand, exile it as it resolves. When you next cast a spell that shares a color with this card, you may cast this from exile without paying its mana cost.)

Flying, lifelink, haste
At the beginning of the end step, sacrifice Helix Entity.

Augmented — If you've spent {W}{U}{B}{R}{G} to cast spells this turn, you may cast this spell without paying its mana cost.
Counter target spell.

Target creature gets +1/+0 for each land you control and gains trample until end of turn.
Orchestrate {1}{G} (You may exile this card from your hand anytime you could cast a sorcery for its orchestrate cost. When you next resolve a spell, you may cast this from exile without paying its mana cost.)

Protection from Dawn Chord (This creature can't be blocked, targeted, dealt damage, or enchanted by anything named Dawn Chord.)
{1}{R}: Target Reflection's base power becomes equal to Dusk Chord's power until end of turn.

Return target permanent card from your graveyard to your hand. You gain 3 life.

Haste

{G}, Tap an untapped Nymph you control: Overgrown Beast gets +2/+2 until end of turn.

When Core Paradigm enters, conjure five cards named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)
Up to three times each turn, you may cast a sorcery spell without paying its mana cost.

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Each creature you control with a counter on it has ward {2}. (If a creature has multiple instances of ward, each triggers separately.)

Danaj Temple enters tapped.
Satrapies you control have “{T}: Add {B} or {G}.”

{T}: Add {C}.
{T}, Pay 1 life: Add {R} or {G}.

The first instant or sorcery spell you cast each turn has convoke. (Each creature you tap while casting that spell pays for {1} or one mana of that creature's color.)

{5}, {T}, Tap an untapped creature you control: Put target card from your or a teammate's graveyard on top of its owner's library.

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
This creature can't be sacrificed.

Flash
Flying
As long as an opponent controls more creatures than you, Arbiter of the Scales gets +2/+2 and has first strike and lifelink.

Ward—Pay 2 life. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays 2 life.)
Heroic — Whenever you cast a spell that targets Hand of Phenax, you draw a card and you lose 1 life. Hand of Phenax gains menace until end of turn.