Flooded Strand

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Shorikai, Genesis Engine

{1}, {T}: Draw two cards, then discard a card. Create a 1/1 colorless Pilot creature token with "This token crews Vehicles as though its power were 2 greater."
Crew 8 (Tap any number of creatures you control with total power 8 or more: This Vehicle becomes an artifact creature until end of turn.)

Hallowed Fountain

({T}: Add {W} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Tundra

Sea of Clouds

This land enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Gemstone Caverns

If this card is in your opening hand and you're not the starting player, you may begin the game with Gemstone Caverns on the battlefield with a luck counter on it. If you do, exile a card from your hand.
{T}: Add {C}. If Gemstone Caverns has a luck counter on it, instead add one mana of any color.