Thought Vessel

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

Navigation Orb

{2}, {T}, Sacrifice Navigation Orb: Search your library for up to two basic land cards and/or Gate cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Deep-Sea Terror

Deep-Sea Terror can't attack unless there are seven or more cards in your graveyard.

Armillary Sphere

{2}, {T}, Sacrifice Armillary Sphere: Search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.

Jace Beleren

+2: Each player draws a card.
−1: Target player draws a card.
−10: Target player mills twenty cards.

Cryptic Serpent

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.

Archaeomancer

When Archaeomancer enters, return target instant or sorcery card from your graveyard to your hand.

Blue Sun's Zenith

Target player draws X cards. Shuffle Blue Sun's Zenith into its owner's library.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Realmbreaker, the Invasion Tree

{2}, {T}: Target opponent mills three cards. Put a land card from their graveyard onto the battlefield tapped under your control. It gains "If this land would leave the battlefield, exile it instead of putting it anywhere else."
{10}, {T}, Sacrifice Realmbreaker, the Invasion Tree: Search your library for any number of Praetor cards, put them onto the battlefield, then shuffle.

River Serpent

River Serpent can't attack unless there are five or more cards in your graveyard.
Cycling {U} ({U}, Discard this card: Draw a card.)

Archmage Ascension

At the beginning of each end step, if you drew two or more cards this turn, you may put a quest counter on Archmage Ascension.
As long as Archmage Ascension has six or more quest counters on it, if you would draw a card, you may instead search your library for a card, put that card into your hand, then shuffle.