msem-instigator

[+1]: Prevent all damage that would be dealt to up to one other target permanent until your next turn.
[–2]: Target creature gets +3/+3 until your next turn.
[–3]: Untap all nonland permanents you control.

Target creature you control becomes a white Bear with base power and toughness 3/5, hexproof, and double strike until end of turn. Whenever it deals combat damage to a player this turn, draw a card.

Archive 6 (As this enters, shuffle the top six cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
You may play Aura and Equipment cards from the archived library, and play those spells as though they had flash.

Flying, vigilance

Lifelink
When Hyctaleon's Vanguard enters, look at the top six cards of your library. You may put a Soldier card with lesser mana value from among them onto the battlefield. Put the rest on the bottom of your library in a random order.
Other Soldiers you control get +1/+1.

Enchant creature
When Hypnotic Halo enters, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
{2}{W}{W}, Sacrifice Hypnotic Halo: Exile enchanted creature.

{1}{W}: Artifact creatures you control get +1/+1 until end of turn. Activate only once each turn.

When Ideologize enters, exile target creature an opponent controls and each other permanent with the same name that player controls. When Ideologize is no longer on the battlefield, return a card exiled with it to the battlefield under its owner's control.

Concord — At the beginning of your upkeep, if there are four or more card types among permanents you control, you gain 1 life and create a 1/1 blue Jellyfish enchantment creature token with slipstream. (It can't be blocked as long as only creatures with slipstream are attacking.)

Flying, vigilance, lifelink
Idyllic Pegasus gets +1/+0 for each artifact and/or enchantment you control.

Search your library for an enchantment card, reveal it, put it into your hand, then shuffle.

Augmented — When you cast If Memory Serves, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, copy it twice. You may choose new targets for the copies.
Return target permanent card with mana value 3 or less from your graveyard to the battlefield. Exile If Memory Serves.

Vigilance
Once each turn, when you cast an instant, sorcery, or Elemental spell, you may put a +1/+1 counter on Ignited Vanguard.

Once each turn, when you gain life, you may exile the top card of your library. You may play that card this turn.
Whenever you cast your second spell each turn, Ignition Engine deals 2 damage to target player or planeswalker.

Trample
Whenever another nontoken creature you control dies, you may return it to the battlefield. It becomes an Aura enchantment with enchant creature you control and “Enchanted creature gets +X/+X, where X is this Aura's mana value.”

{T}, Sacrifice Ilhus, Knight of Zarad: Destroy all creatures.

Target player sacrifices an attacking or blocking creature.

Vigilance
When Illari, Martyrized Tyrant enters, tap all other nonbasic permanents.
Players can't untap more than one nonbasic permanent during each of their untap steps.
When Illari dies, untap all permanents you control and you gain 5 life.

Flying
When Illuminating Archangel enters, target creature gets +X/+X and gains vigilance and first strike until end of turn, where X is the number of permanents you control that are Angels, Demons, Faeries, and/or Spirits.

Whenever Illumination Savant attacks, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Put a +1/+1 counter on each artifact creature and enchantment creature you control.

At the beginning of each opponent's end step, that player gets a poison counter unless damage was dealt this turn.

Flying
Whenever Immaculate Clouddasher attacks, up to three target creatures gain flying until end of turn.

Enchant creature
Enchanted creature gets +3/+3 and has flying.

Indestructible
Immortal Child can't block creatures with greater power.

Hexproof, indestructible
You don't lose the game for having 0 or less life.
For each 1 life you would lose while you have 0 or less life, instead put a -1/-1 counter on a creature you control with toughness 1 or greater.