Magic Damper

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it.

Vault Skyward

Target creature gains flying until end of turn. Untap it.

Xavier Sal, Infested Captain

{T}, Remove a counter from another permanent you control: Populate. Activate only as a sorcery. (Create a token that's a copy of a creature token you control.)
{T}, Sacrifice another creature: Proliferate. Activate only as a sorcery. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Arachnoid Adaptation

Target creature gets +2/+2 and gains reach until end of turn. Untap it.

Burst of Strength

Put a +1/+1 counter on target creature and untap it.

Mobilize

Gift of the Viper

Put a +1/+1 counter, a reach counter, and a deathtouch counter on target creature. Untap it.

High Stride

Target creature gets +1/+3 and gains reach until end of turn. Untap it.

Ornamental Courage

Untap target creature. It gets +1/+3 until end of turn.

Dream's Grip

Choose one —
• Tap target permanent.
• Untap target permanent.
Entwine {1} (Choose both if you pay the entwine cost.)

Legolas's Quick Reflexes

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Untap target creature. Until end of turn, it gains hexproof, reach, and "Whenever this creature becomes tapped, it deals damage equal to its power to up to one target creature."

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Twiddle

You may tap or untap target artifact, creature, or land.

Sudden Spinnerets

Target creature gets +1/+3 until end of turn. Put a reach counter on it. Untap it.

Displacer Kitten

Avoidance — Whenever you cast a noncreature spell, exile up to one target nonland permanent you control, then return that card to the battlefield under its owner's control.

Crab Umbra

Enchant creature
{2}{U}: Untap enchanted creature.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Refocus

Vraska's Fall

Each opponent sacrifices a creature or planeswalker of their choice and gets a poison counter.

Cerulean Wisps

Target creature becomes blue until end of turn. Untap that creature.
Draw a card.

Meekstone

Creatures with power 3 or greater don't untap during their controllers' untap steps.

Minamo, School at Water's Edge

{T}: Add {U}.
{U}, {T}: Untap target legendary permanent.

Leaping Ambush

Teardrop Kami

Sacrifice this creature: You may tap or untap target creature.

Prologue to Phyresis

Each opponent gets a poison counter.
Draw a card.

Vines of the Recluse

Target creature gets +1/+2 and gains reach until end of turn. Untap it. (A creature with reach can block creatures with flying.)

Infectious Bite

Target creature you control deals damage equal to its power to target creature you don't control. Each opponent gets a poison counter.

Ringing Strike Mastery

Enchant creature
When this Aura enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
Enchanted creature has "{5}: Untap this creature."

Vitalize

Mana Vault

This artifact doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap this artifact.
At the beginning of your draw step, if this artifact is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.

Venerated Rotpriest

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Whenever a creature you control becomes the target of a spell, target opponent gets a poison counter.

Emerald Charm

Choose one —
• Untap target permanent.
• Destroy target non-Aura enchantment.
• Target creature loses flying until end of turn.

Instill Energy

Enchant creature
Enchanted creature can attack as though it had haste.
{0}: Untap enchanted creature. Activate only during your turn and only once each turn.

Stony Strength

Put a +1/+1 counter on target creature you control. Untap that creature.

Ichor Rats

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When this creature enters, each player gets a poison counter.

Phyresis Outbreak

Each opponent gets a poison counter. Then each creature your opponents control gets -1/-1 until end of turn for each poison counter its controller has.