how about 'Standard bearer'-bearer'?
A standard-bearer is a person (soldier or civilian) who bears an emblem called an ensign or standard, i.e. either a type of flag or an inflexible but mobile image, which is used (and often honoured) as a formal, visual symbol of a state, prince, military unit, etc. (Wikipedia)
Here's some reference to suggest the importance of a Standard bearer in battle.
The Standard Bearer should never surrender his Banner, if he, during a battle, could no longer safeguard the Banner; he should wrap his body into the Banner awaiting the final slash. (Safeguarding the flag)