Leyline of the Guildpact

If Leyline of the Guildpact 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.

Abuelo, Ancestral Echo

Flying, ward {2}
{1}{W}{U}: Exile another target creature or artifact you control. Return it to the battlefield under its owner's control at the beginning of the next end step.

Agatha of the Vile Cauldron

Activated abilities of creatures you control cost {X} less to activate, where X is Agatha of the Vile Cauldron's power. This effect can't reduce the mana in that cost to less than one mana.
{4}{R}{G}: Other creatures you control get +1/+1 and gain trample and haste until end of turn.

Jodah, the Unifier

Legendary creatures you control get +X/+X, where X is the number of legendary creatures you control.
Whenever you cast a legendary spell from your hand, exile cards from the top of your library until you exile a legendary nonland card with lesser mana value. You may cast that card without paying its mana cost. Put the rest on the bottom of your library in a random order.