The Swarmlord has two +1/+1 counters on each for each time you've cast it from the command zone this game.
Steps
Activate Greater Good by sacrificing The Swarmlord.
Choose to return The Swarmlord to the command zone from your graveyard.
The Swarmlord dies, causing you to draw a card.
Resolve the Greater Good ability, causing you to draw a number of cards equal to The Swarmlord's power, and then discard three cards.
Activate Firemind Vessel by tapping it, adding two mana of different colors.
Activate Mind over Matter by discarding a card, untapping Firemind Vessel.
Repeat from step 5 until you have enough mana to cast The Swarmlord.
Cast The Swarmlord from the command zone by paying ({3} magic symbol) ({U} magic symbol) ({R} magic symbol) ({G} magic symbol) and commander tax, causing The Swarmlord to enter the battlefield with two +1/+1 counters for each time you've cast it from the command zone this game.