Leyline of the Guildpact

If this card is in your opening hand, you may begin the game with it on the battlefield.
Each nonland permanent you control is all colors.
Lands you control are every basic land type in addition to their other types.

Kithkeeper

Vivid — When this creature enters, create X 1/1 green and white Kithkin creature tokens, where X is the number of colors among permanents you control.
Tap three untapped creatures you control: This creature gets +3/+0 and gains flying until end of turn.

Prismabasher

Trample
Vivid — When this creature enters, up to X target creatures you control get +X/+X until end of turn, where X is the number of colors among permanents you control.

Bloom Tender

Vivid — {T}: For each color among permanents you control, add one mana of that color.

Shinestriker

Flying
Vivid — When this creature enters, draw cards equal to the number of colors among permanents you control.

Glister Bairn

Vivid — At the beginning of combat on your turn, another target creature you control gets +X/+X until end of turn, where X is the number of colors among permanents you control.

Shimmercreep

Menace (This creature can't be blocked except by two or more creatures.)
Vivid — When this creature enters, each opponent loses X life and you gain X life, where X is the number of colors among permanents you control.

Explosive Prodigy

Vivid — When this creature enters, it deals X damage to target creature an opponent controls, where X is the number of colors among permanents you control.

Sanar, Innovative First-Year

Vivid — At the beginning of your first main phase, reveal cards from the top of your library until you reveal X nonland cards, where X is the number of colors among permanents you control. For each of those colors, you may exile a card of that color from among the revealed cards. Then shuffle. You may cast the exiled cards this turn.

Rime Chill

Vivid — This spell costs {1} less to cast for each color among permanents you control.
Tap up to two target creatures. Put a stun counter on each of them. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Draw a card.

Squawkroaster

Double strike
Vivid — Squawkroaster's power is equal to the number of colors among permanents you control.

Prismatic Undercurrents

Vivid — When this enchantment enters, search your library for up to X basic land cards, where X is the number of colors among permanents you control. Reveal those cards, put them into your hand, then shuffle.
You may play an additional land on each of your turns.

Wildvine Pummeler

Vivid — This spell costs {1} less to cast for each color among permanents you control.
Reach, trample

Aurora Awakener

Trample
Vivid — When this creature enters, reveal cards from the top of your library until you reveal X permanent cards, where X is the number of colors among permanents you control. Put any number of those permanent cards onto the battlefield, then put the rest of the revealed cards on the bottom of your library in a random order.

Luminollusk

Deathtouch
Vivid — When this creature enters, you gain life equal to the number of colors among permanents you control.