This vicious loop hinges on Thunderblust's persist ability, which brings it back from the dead with a -1/-1 counter whenever it perishes. Woe Strider provides the clean sacrifice outlet to feed this recursion while letting you filter your draws with its scry ability. The magic really happens because Stalwart Successor watches for those counters; its triggered ability places a +1/+1 counter on Thunderblust the first time counters are put on it each turn. That +1/+1 counter immediately neutralizes the incoming -1/+1 counter via state-based actions, leaving Thunderblust completely pristine and ready to be sacrificed to Woe Strider all over again.