Lightning Coils

Whenever a nontoken creature you control dies, put a charge counter on Lightning Coils.
At the beginning of your upkeep, if Lightning Coils has five or more charge counters on it, remove all of them from it and create that many 3/1 red Elemental creature tokens with haste. Exile them at the beginning of the next end step.

Darksteel Citadel

Surge Node

Surge Node enters with six charge counters on it.
{1}, {T}, Remove a charge counter from Surge Node: Put a charge counter on target artifact.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Gitaxian Probe

({U/P} can be paid with either {U} or 2 life.)
Look at target player's hand.
Draw a card.

Myr Servitor

At the beginning of your upkeep, if Myr Servitor is on the battlefield, each player returns all cards named Myr Servitor from their graveyard to the battlefield.

Island

Throne of Geth

{T}, Sacrifice an artifact: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Vault of Whispers

Culling Dais

{T}, Sacrifice a creature: Put a charge counter on Culling Dais.
{1}, Sacrifice Culling Dais: Draw a card for each charge counter on Culling Dais.

Myr Retriever

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

Coretapper

{T}: Put a charge counter on target artifact.
Sacrifice Coretapper: Put two charge counters on target artifact.