Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

River Song

Meet in Reverse — You draw cards from the bottom of your library rather than the top.
Spoilers — Whenever an opponent scries, surveils, or searches their library, put a +1/+1 counter on River Song. Then River Song deals damage to that player equal to its power.

Sulfur Falls

This land enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Talisman of Creativity

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

Izzet Signet

Command Tower

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