Cloak of Mists

Enchant creature
Enchanted creature can't be blocked.

Aether Tunnel

Enchant creature
Enchanted creature gets +1/+0 and can't be blocked.

Candlekeep Sage

Commander creatures you own have "When this creature enters or leaves the battlefield, draw a card."

Ring of Evos Isle

{2}: Equipped creature gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)
At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's blue.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Protective Bubble

Enchant creature
Enchanted creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)

Master Chef

Commander creatures you own have "This creature enters the battlefield with an additional +1/+1 counter on it" and "Other creatures you control enter the battlefield with an additional +1/+1 counter on them."

Evolution Vat

{3}, {T}: Tap target creature and put a +1/+1 counter on it. Until end of turn, that creature gains "{2}{G}{U}: Double the number of +1/+1 counters on this creature."

Expand the Sphere

Look at the top six cards of your library. Put up to two land cards from among them onto the battlefield tapped and the rest on the bottom of your library in a random order. If you put fewer than two lands onto the battlefield this way, proliferate a number of times equal to the difference. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on Forgotten Ancient.
At the beginning of your upkeep, you may move any number of +1/+1 counters from Forgotten Ancient onto other creatures.

Weatherseed Elf

{T}: Target creature gains forestwalk until end of turn. (It can't be blocked as long as defending player controls a Forest.)

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Sword Coast Sailor

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, this creature can't be blocked this turn."

Yargle and Multani

Crypsis

Target creature you control gains protection from creatures your opponents control until end of turn. Untap it.

Tavern Brawler

Commander creatures you own have "At the beginning of your upkeep, exile the top card of your library. This creature gets +X/+0 until end of turn, where X is that card's mana value. You may play that card this turn."

Slip Through Space

Devoid (This card has no color.)
Target creature can't be blocked this turn.
Draw a card.

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Master Biomancer

Each other creature you control enters the battlefield with a number of additional +1/+1 counters on it equal to Master Biomancer's power and as a Mutant in addition to its other types.

Veil of Secrecy

Target creature gains shroud until end of turn and can't be blocked this turn. (A creature with shroud can't be the target of spells or abilities.)
Splice onto Arcane—Return a blue creature you control to its owner's hand. (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Fangren Firstborn

Whenever Fangren Firstborn attacks, put a +1/+1 counter on each attacking creature.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Shaman of the Great Hunt

Haste
Whenever a creature you control deals combat damage to a player, put a +1/+1 counter on it.
Ferocious — {2}{G/U}{G/U}: Draw a card for each creature you control with power 4 or greater.

Yargle, Glutton of Urborg

Distortion Strike

Target creature gets +1/+0 until end of turn and can't be blocked this turn.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Farhaven Elf

When Farhaven Elf enters the battlefield, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Artful Dodge

Target creature can't be blocked this turn.
Flashback {U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Infiltrate

Target creature can't be blocked this turn.

Trap Essence

Counter target creature spell. Put two +1/+1 counters on up to one target creature.