Conversation so far:
What was a famous work that came out during the Mystical-abstract period?
Fohn im Marc'schen Garten (Foehn at Marc's Garden) was made after the Turin trip.
What other painters were famous during this period?
in the fashion of Paul Cezanne and Robert Delaunays' cubistic form concepts.

Question: Was World War I important in the Mystical-abstract period?
Self-contained rewrite: Was World War I important in the Mystical-abstract period?