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Sekki, Seasons' Guide enters the battlefield with eight +1/+1 counters on it.
If damage would be dealt to Sekki, prevent that damage, remove that many +1/+1 counters from Sekki, and create that many 1/1 colorless Spirit creature tokens.
Sacrifice eight Spirits: Return Sekki from your graveyard to the battlefield.
You can sacrifice any eight Spirits to pay for Sekki’s activated ability, not just the Spirit creature tokens.
Creature tokens are put onto the battlefield even if there are no more +1/+1 counters to remove. For example, attempting to deal 9 damage to Sekki causes its replacement effect to 1) prevent the 9 damage, 2) remove all eight of the +1/+1 counters, and 3) put nine Spirit creature tokens onto the battlefield.
Damage that can’t be prevented still causes counters to be removed from Sekki and puts creature tokens onto the battlefield.
Increasing Sekki’s toughness with a card like Indomitable Will allows Sekki to prevent damage and make tokens even it if has no +1/+1 counters to be removed.
