Vigilance

Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell.

Sacrifice Boromir, Warden of the Tower: Creatures you control gain indestructible until end of turn. The Ring tempts you.

At the beginning of your upkeep, the Ring tempts you.

Whenever you choose a creature as your Ring-bearer, you may pay 2 life. If you do, draw a card.

Destroy target creature. The Ring tempts you.

Whenever one or more creatures attack, you may have target attacking creature gain double strike until end of turn.

{W/B}{W/B}: If Frodo, Sauron's Bane is a Citizen, it becomes a Halfling Scout with base power and toughness 2/3 and lifelink.

{B}{B}{B}: If Frodo is a Scout, it becomes a Halfling Rogue with "Whenever this creature deals combat damage to a player, that player loses the game if the Ring has tempted you four or more times this game. Otherwise, the Ring tempts you."

Deathtouch

When Nazgûl enters the battlefield, the Ring tempts you.

Whenever the Ring tempts you, put a +1/+1 counter on each Wraith you control.

A deck can have up to nine cards named Nazgûl.

Return target creature card from your graveyard to your hand. The Ring tempts you.

Exile target creature you own, then return it to the battlefield under your control. The Ring tempts you.

Flying

Whenever one or more creatures deal combat damage to you, each opponent sacrifices a creature that dealt combat damage to you this turn. The Ring tempts you.

Discard a card: Witch-king of Angmar gains indestructible until end of turn. Tap it.