2021-09-24 : If some, but not all, of the target creatures are illegal targets as Defend the Celestus resolves, the original distribution of counters remains the same. Counters that were to be put on the now-illegal targets are lost.

2021-09-24 : You decide how to distribute the counters as you cast Defend the Celestus. You must distribute at least one counter to each creature you target.