The First Sword was one of the legendary first 6 high-ranking mechs of the Larkinson Clan.
The first 6 possessed the greatest fame and prestige due to their long history of turning battles around and securing decisive victories.
The original incarnations of the Dark Zephyr, the Amaranto, the First Sword, the Riot, the Shield of Samar and the Everchanger represented the initial generation of expert mechs and played key roles in setting up the Larkinson Clan for success.
The clan wouldn't exist without their deeds. Ves was able to become the most successful mech designer of his generation because of how they managed to overcome one challenger after another.
Although subsequent machines such as the Promethea, the Minerva and the Phobos performed considerably more dramatically in combat, they were products of a younger era. This also included the Bastion which was the successor to the Shield of Samar.