up-and-comer
Someone who displays signs of or potential for ambitious development, advancement, and achievement. That new intern we hired certainly is an up-and-comer, don't you think? I wouldn't be surprised if she ended up running this place someday. He might not have won the championship round, but this amateur is definitely an up-and-comer!
all comers
Everyone who expresses an interest in being involved in or with something. Every club on campus has to accept all comers—no one is to be excluded.
all comers
anyone who chooses to take part in an activity, typically a competition. 1992 Al Gore Earth in the Balance He has traveled to conferences and symposia in every part of the world, argued his case, and patiently taken on all comers.
comer
(ˈkəmɚ) n. someone with a bright future. Fred is a real comer. You’ll be hearing a lot about him.