You see, you can pay one Blue mana and sacrifice it to counter a spell or ability that targets you or a creature you control
Decks that make use of +1/+1 counters might be interested in including Clay Champion, as the open-ended aspect of the casting cost means you can distribute as many counters as youve got colored mana
Sample Decklist The deck contains 35 creatures, four sorceries, nine instants, 16 artifacts, one enchantment, and 34 lands
After any die is rolled, before applying the result of that die, there's an opportunity for you to use those effects
If you have two other Nazgls in play and play a third, each gets three +1/+1 counters: one from the two already on the battlefield and the third from the third entering