Leyline of Abundance

If Leyline of Abundance is in your opening hand, you may begin the game with it on the battlefield.
Whenever you tap a creature for mana, add an additional {G}.
{6}{G}{G}: Put a +1/+1 counter on each creature you control.

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Arbor Elf

Summer Bloom

You may play up to three additional lands this turn.

Llanowar Elves

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Harmonize

Llanowar Visionary

When Llanowar Visionary enters, draw a card.
{T}: Add {G}.

Explore

You may play an additional land this turn.
Draw a card.

Incoming!

Each player searches their library for any number of artifact, creature, enchantment, and/or land cards, puts them onto the battlefield, then shuffles.

Helix Pinnacle

Shroud (This enchantment can't be the target of spells or abilities.)
{X}: Put X tower counters on Helix Pinnacle.
At the beginning of your upkeep, if there are 100 or more tower counters on Helix Pinnacle, you win the game.