To help hit that critical mass, Id look to cards like Scute Swarm, Hornet Queen, and Avenger of Zendikar
Its a staple in combo decks across Legacy, Commander, and now-fringe Standard brews, and once resolved, it almost always ends the game in a flood of spells
Be sure to include many fodder artifacts, which you can sacrifice for huge mana payoffs like Triplicate Titan, Chiss-Goria, Forge Tyrant, Myr Battlesphere, and Cityscape Leveler
The defending player can then choose whether to play a Counter card from their hand, trashing a character card in order to add the specified Counter value to the defending card's power or an event card to activate the effect as explained on the card
Not only can this card find another one of the powerful Land of Wano cards in your deck, pairing it with the Yamato leader effect will give an extra swing that could close out the game for you