What's "the word I'm thinking of"? Today, it's...
ICARIAN [ih-KAIR-ee-UHN] (adjective or noun)
Having qualities similar to the Greek mythological character Icarus, especially his excessive ambition and recklessness
"Predictably, the hazardous displays of the Icarian are prone to provoke countertransference reactions that, much like a failed parachute, collapse an analytic attitude."
--Terrence McBride, Maureen Murphy, "Trauma and the Destructive-Transformative Struggle" (2019)