msem-instigator

Whenever you cast a noncreature spell, create a 1/1 colorless Construct artifact creature token.

Lifelink
Augmented — Whenever you cast a spell, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on United Guardian. It loses this ability and gains “Whenever United Guardian attacks, create two 1/1 blue Elemental creature tokens with flying that are tapped and attacking.”

Until end of turn, you can't lose the game, your opponents can't win the game, and your life total can't change.

Choose one, then choose another for each card named Unraveling in your graveyard.
• Counter up to one target spell.
• Scry 2, then draw a card.
• Up to three target lands your opponents control don't untap during their controller's next untap step.
• Creatures your opponents control get -4/-0 until end of turn.

This spell costs {2} less to cast if your starting deck contained at least forty cards more than the minimum deck size.
When Unrivaled Fireweaver enters, you may exile a red instant or sorcery card you own from outside the game. Until the end of your next turn, you may play that card.

All creatures have “When this creature enters, destroy target creature with a lesser mana value.”

Starting with the next opponent in turn order, each player sacrifices a permanent. Repeat this process until the total mana value of all permanents sacrificed this way is 13 or greater, or until thirteen or more permanents have been sacrificed this way, or until there are no nonland permanents on the battlefield, whichever happens first. Exile Utter Pandemonium.

Exile all lands. For each land card exiled this way, Uttermost Obliteration deals 1 damage to that land's controller.

As Vaertris' Master Plan enters, exile the top five cards of any player's library.
You may play cards exiled with Vaertris' Master Plan.
When there are no cards exiled with Vaertris' Master Plan, return it to its owner's hand.

[+1]: Until end of turn, whenever target creature deals combat damage to a player, that player mills two cards.
[–1]: Tap target creature. It can't become untapped for as long as you control Vaertris, Mindmelder.
[–6]: You get an emblem with “Whenever you draw a card, target player mills three cards” and “{2}{U}: Draw a card.”

As long as an opponent has one or fewer cards in hand, Valdez gets +2/+0 and has menace.

Whenever you cast a spell that targets, put a loyalty counter on Valeri Kripac and create a 1/1 white Soldier creature token.
[+1]: Add {R}. If you spend this mana on a spell that targets, that spell can't be countered.
[–2]: Exile target instant or sorcery card from your graveyard. You may play it until the end of your next turn. If you do, exile that spell instead of putting it anywhere else.

Whenever another artifact is put into your graveyard from the battlefield, each opponent loses 1 life and you gain 1 life.

Flash
When Veilborn Meddler enters, counter target spell if its mana value is less than or equal to Veilborn Meddler's power.
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on Veilborn Meddler.

[+2]: Destroy up to one target monocolored permanent.
[–3]: Create an 8/8 Elemental creature token with flying, first strike, vigilance, trample, and lifelink that's all colors.
[–5]: Draw three cards. You pay {0} rather than pay the mana cost for the next spell you cast this turn.

As this permanent transforms into Velir, put four loyalty counters on it.
[+1]: Draw two cards, then discard two cards unless you discard a land card.
[–2]: Search your library for a multicolored card, reveal it, put it into your hand, then shuffle.
[–4]: Exile target permanent.

Codex — Heraldry; Whimsy; Villainy; Creativity; Brutality. (As this enters, conjure its contents into a shuffled face-up additional library.)
You may spend mana as though it were mana of any color to cast this codex's contents.
Spells you cast are all colors.

Haste
When Vidal enters, reveal cards from the top of your library until you reveal an enchantment card with mana value 3 or less. Put that card onto the battlefield and the rest on the bottom of your library in a random order. Sacrifice that enchantment at the beginning of the next end step.

Deathtouch, protection from legendary
Vielle, Undercity Wayfarer has all loyalty abilities of permanents on the battlefield that cost +1, +0, or -1. (Before cost changes. Add or remove loyalty counters from Vielle to pay their loyalty costs.)

Whenever one or more creatures die for the first time each turn, you draw a card and you lose 1 life.
Whenever you cast a black noncreature spell, Villainy deals 2 damage to any target and you gain 2 life.

First mate—Your starting deck contains one or more cards of exactly each color and each color pair. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
During each of your turns, you may cast a card of each color from your graveyard. If a spell cast this way would be put into your graveyard, exile it instead.

Once each turn, you may activate an additional loyalty ability of a planeswalker you control.
[+1]: You gain 1 life for each loyalty ability you've activated this turn. Scry 1.
[0]: Put a +1/+1 counter on target creature. It can't attack or block until your next turn.
[–3]: Exile target creature with power 4 or greater.

Vitalhydra enters with twice X +1/+1 counters on it.
Each other creature you control enters with a number of additional +1/+1 counters on it equal to the number of +1/+1 counters on Vitalhydra.

[+1]: Exile up to one other target permanent until the beginning of its owner's next end step.
[–1]: Return another target planeswalker to its owner's hand.
[–6]: You get an emblem with “Whenever a permanent leaves the battlefield, each opponent discards a card.”