The One Ring

Indestructible
When The One Ring enters, if you cast it, you gain protection from everything until your next turn.
At the beginning of your upkeep, you lose 1 life for each burden counter on The One Ring.
{T}: Put a burden counter on The One Ring, then draw a card for each burden counter on The One Ring.

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. This artifact deals 1 damage to you.

Sol Ring

Arcane Signet

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

Dimir Signet

Ormacar, Relic Wraith

Vigilance, menace, lifelink
Precious (You can have two commanders if the other one is a legendary noncreature artifact.)
As long as you control your Precious, Ormacar gets +X/+X, where X is the mana value of your Precious.