You may exert Vizier of the True as it attacks. (It won't untap during your next untap step.)
Whenever you exert a creature, tap target creature an opponent controls.

: Add . Spend this mana only to cast an instant or sorcery spell.

, : Target creature phases out. (While it's phased out, it's treated as though it doesn't exist. It phases in before its controller untaps during their next untap step.)

First strike
Vodalian Knights can't attack unless defending player controls an Island.
When you control no Islands, sacrifice Vodalian Knights.
: Vodalian Knights gains flying until end of turn.

, : Counter target spell unless its controller pays .

When Vodalian Merchant enters the battlefield, draw a card, then discard a card.

: Target instant or sorcery spell becomes the color of your choice.

Kicker (You may pay an additional as you cast this spell.)
Vodalian Serpent can't attack unless defending player controls an Island.
If Vodalian Serpent was kicked, it enters the battlefield with four +1/+1 counters on it.

Defender (This creature can't attack.)
Tap an untapped Merfolk you control: Vodalian War Machine can attack this turn as though it didn't have defender.
Tap an untapped Merfolk you control: Vodalian War Machine gets +2/+1 until end of turn.
When Vodalian War Machine dies, destroy all Merfolk tapped this turn to pay for its abilities.

Flying
As Voice of All enters the battlefield, choose a color.
Voice of All has protection from the chosen color.

Flying, protection from green

Flying, protection from black

Flying, protection from red

Flying, protection from blue

Flying, protection from white

Flying
When Voice of the Provinces enters the battlefield, create a 1/1 white Human creature token.

Flying, first strike

Devoid (This card has no color.)
Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.