Gigadrowse

Replicate {U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Tap target permanent.

Curse of Inertia

Enchant player
Whenever a player attacks enchanted player with one or more creatures, that attacking player may tap or untap target permanent of their choice.

Ghostly Touch

Enchant creature
Enchanted creature has "Whenever this creature attacks, you may tap or untap target permanent."

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Braided Quipu

{3}{U}, {T}: Draw a card for each artifact you control, then put this artifact into its owner's library third from the top.

Braided Net

This artifact enters with three net counters on it.
{T}, Remove a net counter from this artifact: Tap another target nonland permanent. Its activated abilities can't be activated for as long as it remains tapped.
Craft with artifact {1}{U}

Braided Net // Braided Quipu

Frost Titan

Whenever this creature becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {2}.
Whenever this creature enters or attacks, tap target permanent. It doesn't untap during its controller's next untap step.

Kelpie Guide

{T}: Untap another target permanent you control.
{T}: Tap target permanent. Activate only if you control eight or more lands.

Dreamtide Whale

Vanishing 2 (This creature enters with two time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Whenever a player casts their second spell each turn, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Sol Ring

Grappling Kraken

Landfall — Whenever a land you control enters, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Hylda of the Icy Crown

Whenever you tap an untapped creature an opponent controls, you may pay {1}. When you do, choose one —
• Create a 4/4 white and blue Elemental creature token.
• Put a +1/+1 counter on each creature you control.
• Scry 2, then draw a card.