First Sage Esmus leads the denizens of Mithrava on Havarl, and as such is an exemplar of conventional beliefs among his people.
The First Sage greets Pathfinder Ryder when they first arrive at Mithrava, surprised that an alien is able to bypass the sages' security measures. Since they don't accept visitors he asks Ryder to leave, but the Pathfinder argues they can do something to reverse Havarl's decline. Esmus tells them it's a lost cause as the location of the third monolith required for normal vault function has also been lost.
Esmus gives Ryder an intro to angara beliefs in reincarnation. Zorai, a legendary pre-Scourge angara, knew about the third monolith. He had a heirloom that might help his descendants remember the location, but the heirloom is lost in Remnant territory and the angara believed to be Zorai's reincarnation, Taavos, is now a xenophobic Roekaar soldier.
The First Sage initially thinks nothing could be done about the issue. But with the Pathfinder's demonstrated prowess, he now believes there's hope. He gives Ryder the last known coordinates of Zorai's heirloom at Remnant Abyss.
When Ryder rediscovers the lost monolith and resets the vault, Esmus congratulates them for they succeeded where Zorai and Mithrava failed. Esmus regains faith in Havarl seeing that aliens are working for something he had given up. He ultimately leaves the tower to renew old bonds with the other angara on Havarl because he now thinks that Mithrava's people have isolated themselves for too long. A new balance needs to be found.