Black Mana Battery

{2}, {T}: Put a charge counter on this artifact.
{T}, Remove any number of charge counters from this artifact: Add {B}, then add an additional {B} for each charge counter removed this way.

Chimeric Egg

Whenever an opponent casts a nonartifact spell, put a charge counter on this artifact.
Remove three charge counters from this artifact: This artifact becomes a 6/6 Construct artifact creature with trample until end of turn.

Angelheart Vial

Whenever you're dealt damage, you may put that many charge counters on this artifact.
{2}, {T}, Remove four charge counters from this artifact: You gain 2 life and draw a card.

Blue Mana Battery

{2}, {T}: Put a charge counter on this artifact.
{T}, Remove any number of charge counters from this artifact: Add {U}, then add an additional {U} for each charge counter removed this way.

Red Mana Battery

{2}, {T}: Put a charge counter on this artifact.
{T}, Remove any number of charge counters from this artifact: Add {R}, then add an additional {R} for each charge counter removed this way.

Aether Vial

At the beginning of your upkeep, you may put a charge counter on this artifact.
{T}: You may put a creature card with mana value equal to the number of charge counters on this artifact from your hand onto the battlefield.

Blast Zone

This land enters with a charge counter on it.
{T}: Add {C}.
{X}{X}, {T}: Put X charge counters on this land.
{3}, {T}, Sacrifice this land: Destroy each nonland permanent with mana value equal to the number of charge counters on this land.