You may spend mana as though it were mana of any color to activate abilities of creatures you control.
Creatures you control with +1/+1 counters on them have all activated abilities of all creature cards exiled with Agatha's Soul Cauldron.
{T}: Exile target card from a graveyard. When a creature card is exiled this way, put a +1/+1 counter on target creature you control.
{1}{B}
Francisco, Fowl Marauder
Legendary Creature - Bird Pirate
Flying
Francisco, Fowl Marauder can't block.
Whenever one or more Pirates you control deal damage to a player, Francisco explores.
Partner (You can have two commanders if both have partner.)
0 /
1
{2}{U}
Malcolm, Keen-Eyed Navigator
Legendary Creature - Siren Pirate
Flying
Whenever one or more Pirates you control deal damage to your opponents, you create a Treasure token for each opponent dealt damage. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Partner (You can have two commanders if both have partner.)
2 /
2
{1}{B}
Marionette Apprentice
Creature - Human Artificer
Fabricate 1 (When this creature enters the battlefield, put a +1/+1 counter on it or create a 1/1 colorless Servo artifact creature token.)
Whenever another creature or artifact you control is put into a graveyard from the battlefield, each opponent loses 1 life.
1 /
2
{2}{U}{B}
Talion, the Kindly Lord
Legendary Creature - Faerie Noble
Flying
As Talion, the Kindly Lord enters the battlefield, choose a number between 1 and 10.
Whenever an opponent casts a spell with mana value, power, or toughness equal to the chosen number, that player loses 2 life and you draw a card.