Arcane Signet

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

Isochron Scepter

Imprint — When Isochron Scepter enters, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.

Elsha of the Infinite

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
You may look at the top card of your library any time.
You may cast noncreature spells from the top of your library. If you cast a spell this way, you may cast it as though it had flash.

Jeweled Lotus

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

Mishra's Bauble

{T}, Sacrifice Mishra's Bauble: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.