Sword of the Paruns

As long as equipped creature is tapped, tapped creatures you control get +2/+0.
As long as equipped creature is untapped, untapped creatures you control get +0/+2.
{3}: You may tap or untap equipped creature.
Equip {3}

Doubling Cube

{3}, {T}: Double the amount of each type of unspent mana you have.

Redshift, Rocketeer Chief

Vigilance
{T}: Add X mana of any one color, where X is Redshift's power. Spend this mana only to activate abilities.
Exhaust — {10}{R}{G}: Put any number of permanent cards from your hand onto the battlefield. (Activate each exhaust ability only once.)

Goblin Engineer

When this creature enters, you may search your library for an artifact card, put it into your graveyard, then shuffle.
{R}, {T}, Sacrifice an artifact: Return target artifact card with mana value 3 or less from your graveyard to the battlefield.

Godo, Bandit Warlord

When Godo enters, you may search your library for an Equipment card, put it onto the battlefield, then shuffle.
Whenever Godo attacks for the first time each turn, untap it and all Samurai you control. After this phase, there is an additional combat phase.

Prismite

Omnath, Locus of Mana

You don't lose unspent green mana as steps and phases end.
Omnath gets +1/+1 for each unspent green mana you have.