Adjective for someone who accepts all challenges
Closest thing i can think of is:
dauntless
adjective literary
UK /ˈdɔːnt.ləs/ US /ˈdɑːnt.ləs/
showing determination and no fear:
In spite of the scale of the famine, the relief workers struggled on with dauntless optimism.
https://dictionary.cambridge.org/dictionary/english/dauntless