Swamp

Law-Rune Enforcer

{1}, {T}: Tap target creature with mana value 2 or greater.

Assassin Initiate

{1}: Assassin Initiate gains your choice of flying, deathtouch, or lifelink until end of turn.

Mardu Hateblade

{B}: Mardu Hateblade gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Doomed Traveler

When Doomed Traveler dies, create a 1/1 white Spirit creature token with flying.

Plains

Valgavoth's Faithful

{3}{B}, Sacrifice Valgavoth's Faithful: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.

MacCready, Lamplight Mayor

Whenever a creature you control with power 2 or less attacks, it gains skulk until end of turn. (It can't be blocked by creatures with greater power.)
Whenever a creature with power 4 or greater attacks you, its controller loses 2 life and you gain 2 life.