The worst "Hero programmer" behavior of middle management and senior developers I have seen:
- no help during on-boarding
- no interest in helping or sharing information during work
- constant posing as a hero to save the day on any occasion possible in front of higher Management whenever a new hire makes a mistake or has not enough information to do the work.
They hire you as a feature developer, but you get mostly unit test development and bug fixing work. They won't let you promote to next level, unless you are willing to move to a test engineer role.