Heartbeat of Spring

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Ugin, the Ineffable

Colorless spells you cast cost {2} less to cast.
+1: Exile the top card of your library face down and look at it. Create a 2/2 colorless Spirit creature token. When that token leaves the battlefield, put the exiled card into your hand.
−3: Destroy target permanent that's one or more colors.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Ornithopter of Paradise

Workshop Assistant

When Workshop Assistant dies, return another target artifact card from your graveyard to your hand.

Selesnya Signet

Strionic Resonator

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Boros Signet

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Daretti, Scrap Savant

+2: Discard up to two cards, then draw that many cards.
−2: Sacrifice an artifact. If you do, return target artifact card from your graveyard to the battlefield.
−10: You get an emblem with "Whenever an artifact is put into your graveyard from the battlefield, return that card to the battlefield at the beginning of the next end step."
Daretti, Scrap Savant can be your commander.

Gruul Signet

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Asceticism

Creatures you control have hexproof.
{1}{G}: Regenerate target creature. (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.

Eladamri's Call

Search your library for a creature card, reveal that card, put it into your hand, then shuffle.

Explosive Vegetation

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Wurmcoil Engine

Deathtouch, lifelink
When Wurmcoil Engine dies, create a 3/3 colorless Phyrexian Wurm artifact creature token with deathtouch and a 3/3 colorless Phyrexian Wurm artifact creature token with lifelink.

Sculpting Steel

You may have Sculpting Steel enter as a copy of any artifact on the battlefield.

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

Elvish Piper

{G}, {T}: You may put a creature card from your hand onto the battlefield.

Brilliant Restoration

Return all artifact and enchantment cards from your graveyard to the battlefield.