Sekki prevents the damage dealt by Terror of the Peaks and instead removes eight +1/+1 counters from itself and creates eight 1/1 Spirit creature tokens.
Sekki dies as a state-based action due to having zero toughness.
Terror of the Peaks triggers eight times, dealing 8 damage to any target(s).
Activate Sekki by sacrificing eight Spirits, returning Sekki from your graveyard to the battlefield.