Veteran

A veteran was an active participant in, and is a suvivor of, one or more military campaigns, who has since retired to civilian life. Veterans know all too well the horrrors of the battlefield and have the (physical and perhaps also mental) scars to prove it. Retired militarymen are veterans. Strahd von Zarovich is, for example, a veteran.

Veteran may also be used to describe an individual's competence in a violent and dangerous profession. A veteran mercenary or a veteran adventurer is experienced and battle-tested. Dr. Rudolph van Richten was, for example, a veteran monster hunter