msem-instigator

If you would lose life, exile that many cards from the top of your library instead.
If you would gain life, draw that many cards instead.
When Unhallowed Concordat leaves the battlefield, you lose life equal to the number of cards you own in exile.

As an additional cost to cast this spell, exile X cards from your graveyard.
Create X tapped 2/2 black Zombie creature tokens.

Menace
{3}{B}, Discard a card: Unhallowed Singers gets +3/+0 until end of turn. Whenever it deals combat damage to a player this turn, they discard a card.

Destroy target creature with total power and toughness 8 or less.

Starting with you, each player may sacrifice a creature. Each player that doesn't loses life equal to the total power of creatures sacrificed this way.

Target creature can't block until end of turn. If that creature had a Steed attached to it, unattach that Steed and it can't block until end of turn.
Draw a card.

{T}: Add one mana of any color.
{T}, Sacrifice Unicorn of the Vale: Add three mana of any one color.

Whenever you cast an enchantment spell, reveal the top card of your library. If it's an enchantment card, you may put it onto the battlefield.

If you would draw a card, you may return an instant or sorcery card from your graveyard to your hand instead.
{U}: Draw three cards.

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

When Unite Against Evil enters, return target creature card with mana value 3 or less from your graveyard to the battlefield.
Menagerie — Whenever you attack, if there are five or more creature types among creatures you control, put a +1/+1 counter on target attacking creature and untap it.

Look at the top six cards of your library. Put up to two creature cards with mana value 3 or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order. Then you gain 1 life for each Angel, Demon, Faerie, and/or Spirit you control.

Each artifact you control has all the activated abilities of other artifacts you control.

Exile the top five cards of your library. Until end of turn, you may play any number of cards exiled this way with mana value less than or equal to the number of colors among permanents you controlled as you cast United Fervor.

Enchant creature
As long as it's your turn, enchanted creature has indestructible.
Whenever enchanted creature attacks, it deals damage equal to its toughness to any target.

Create X 1/1 white Nymph creature tokens. Until end of turn, creatures you control gain protection from each color among permanents you controlled as you cast United Force.

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.”

Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)
United Patrol can block an additional creature each combat.

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

When United in Battle enters, look at the top six cards of your library. You may reveal a Dwarf or Elf card from among them and put it into your hand. Put the rest on the bottom in a random order.
Whenever a Dwarf or Elf you control enters, put a +1/+1 counter on it.

When Unity Spheres enters, create two 1/1 colorless Construct artifact creature tokens.
Tap two untapped creatures you control: Add two mana of any one color.

Other creatures you control get +1/+0.
At the beginning of combat on your turn, create a 1/1 red Human creature token with haste.

University Archive enters tapped.
When University Archive enters, look at the top card of your library. You may put it into your graveyard.
{T}: Add {U} or {R}.

Target player loses 3 life.