challengeful
/ˌtʃælɪnʒˈfʊl/Definitions
1. adjective
predisposed to issue challenges or invitations to engage in competition or to take on a difficult task
“He’s a challengeful opponent, always pushing us to be our best.”
2. noun
the quality of being inclined to issue challenges or invitations to engage in competition or to take on a difficult task
“His challengeful nature made him a great leader in team sports.”