Teferi's Ageless Insight

If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Arcane Signet

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

At the beginning of each end step, if an opponent lost 3 or more life this turn, you may draw a card. (Damage causes loss of life.)

Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Morphic Pool enters the battlefield tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

({T}: Add {U} or {B}.)
As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

All creatures have "At the beginning of your upkeep, sacrifice this creature unless you pay 1 life."

Whenever a creature you control deals combat damage to a player, that player discards a card.

Whenever a creature attacks you, its controller loses 1 life.

Whenever a creature you control deals combat damage to a player, you may draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)