Helm of Possession

You may choose not to untap Helm of Possession during your untap step.
{2}, {T}, Sacrifice a creature: Gain control of target creature for as long as you control Helm of Possession and Helm of Possession remains tapped.

Agent of Treachery

When Agent of Treachery enters, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

Seasinger

When you control no Islands, sacrifice Seasinger.
You may choose not to untap Seasinger during your untap step.
{T}: Gain control of target creature whose controller controls an Island for as long as you control Seasinger and Seasinger remains tapped.

Vedalken Shackles

You may choose not to untap Vedalken Shackles during your untap step.
{2}, {T}: Gain control of target creature with power less than or equal to the number of Islands you control for as long as Vedalken Shackles remains tapped.

Callous Oppressor

You may choose not to untap Callous Oppressor during your untap step.
As Callous Oppressor enters, an opponent chooses a creature type.
{T}: Gain control of target creature that isn't of the chosen type for as long as Callous Oppressor remains tapped.

Conjurer's Closet

At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.

Sower of Temptation

Flying
When Sower of Temptation enters, gain control of target creature for as long as Sower of Temptation remains on the battlefield.

Blatant Thievery

For each opponent, gain control of target permanent that player controls.

Roil Elemental

Flying
Landfall — Whenever a land you control enters, you may gain control of target creature for as long as you control Roil Elemental.

Chamber of Manipulation

Enchant land
Enchanted land has "{T}, Discard a card: Gain control of target creature until end of turn."

Captivating Glance

Enchant creature
At the beginning of your end step, clash with an opponent. If you win, gain control of enchanted creature. Otherwise, that player gains control of enchanted creature. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Ray of Command

Untap target creature an opponent controls and gain control of it until end of turn. That creature gains haste until end of turn. When you lose control of the creature, tap it.

Thassa, Deep-Dwelling

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control.
{3}{U}: Tap another target creature.

Domineering Will

Target player gains control of up to three target nonattacking creatures until end of turn. Untap those creatures. They block this turn if able.

Overtaker

{3}{U}, {T}, Discard a card: Untap target creature and gain control of it until end of turn. That creature gains haste until end of turn.