Instant Color tag templates(None) Narset's Reversal Copy target instant or sorcery spell, then return it to its owner's hand
Besides +1/+1 counters, you've got plenty of ways to boost the power and toughness of your merfolk army , like Merfolk Mistbinder, Merfolk Sovereign, and Merrow Reejerey
Remember, these cards care about how much mana you actually spent on the spell, not the printed mana value so the higher tiers of Ice Magic and Thunder Magic, the flashback casts of Dreams of Laguna and Laughing Mad, and a big Syncopate or Choco-Comet will all work to trigger your stuff
Uniquely, the front side of this card is a Legendary Creature, which can be a commander
Instant Color tag templates(None) March of the Multitudes Convoke (Your creatures can help cast this spell