Well of Lost Dreams

Whenever you gain life, you may pay {X}, where X is less than or equal to the amount of life you gained. If you do, draw X cards.

Revitalize

Ivory Tower

At the beginning of your upkeep, you gain X life, where X is the number of cards in your hand minus 4.

Fountain of Renewal

At the beginning of your upkeep, you gain 1 life.
{3}, Sacrifice Fountain of Renewal: Draw a card.

Will, Scion of Peace

Vigilance
{T}: Spells you cast this turn that are white and/or blue cost {X} less to cast, where X is the amount of life you gained this turn. Activate only as a sorcery.

Drogskol Reaver

Flying
Double strike (This creature deals both first-strike and regular combat damage.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Whenever you gain life, draw a card.