Conversation so far:
What is the great white owl relating to Cassandra Nova?
On Earth-TRN342, Cassandra Nova has somehow survived for four thousand years and nearly conquered the world as the Great White Owl
who nearly conquered the world as the Great White Owl?
Cassandra Nova nearly conquered the world as the Great White Owl
Was Cassandra Nova the Great white owl?
Cassandra Nova was the Great White Owl

Question: what does she do while she is the Great white owl?
Self-contained rewrite: what does Cassandra Nova do while she is the Great white owl?