Fear of Isolation

As an additional cost to cast this spell, return a permanent you control to its owner's hand.
Flying

Isolation Cell

Whenever an opponent casts a creature spell, that player loses 2 life unless they pay {2}.

Solitary Confinement

At the beginning of your upkeep, sacrifice this enchantment unless you discard a card.
Skip your draw step.
You have shroud. (You can't be the target of spells or abilities.)
Prevent all damage that would be dealt to you.

Solitude

Flash
Lifelink
When this creature enters, exile up to one other target creature. That creature's controller gains life equal to its power.
Evoke—Exile a white card from your hand.

Solitary Sanctuary

When this enchantment 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.)
Whenever you tap an untapped creature an opponent controls, put a +1/+1 counter on target creature you control.

Isolation at Orthanc

Put target creature into its owner's library second from the top.

Isolated Watchtower

{T}: Add {C}.
{2}, {T}: Scry 1, then you may reveal the top card of your library. If a basic land card is revealed this way, put it onto the battlefield tapped. Activate only if an opponent controls at least two more lands than you.

Eternal Isolation

Put target creature with power 4 or greater on the bottom of its owner's library.

Temporal Isolation

Flash
Enchant creature
Enchanted creature has shadow. (It can block or be blocked by only creatures with shadow.)
Prevent all damage that would be dealt by enchanted creature.

Isolation Zone

When this enchantment enters, exile target creature or enchantment an opponent controls until this enchantment leaves the battlefield. (That permanent returns under its owner's control.)