No nononono, "THERE'S A THOUSAND THINGS I HAVEN'T DONE BUT JUST YOU WAIT" is a Slytherin quality! That's ambition!

The Gryffindor comes in with his inability/unwillingness to hide how he really feels about anything/anyone, and his frustration at being sidelined from the actual fighting, and his bone-deep certainty that he and his side will win because they're morally in the right.