Isaiah

Isaiah was the director of The Aerie, an Abstergo Industries complex and a member of the Templar Order.

Biography
In 2016, after the Templars captured a team of teenagers using a stolen Animus to find the Trident of Eden under the guidance of Monroe, Isaiah and Victoria Bibeau tried to discover what they knew.

In order to do so, the two Templars decided to use honesty, Isaiah confirming that there were both members of the Templar Order and that Abstergo was indeed a front for the secret society, but insisting on the benevolence of their organization. They succesfully convinced some members of the group, who then revealed to the Templars the location of a Dagger of Eden, actually one of the prongs of the Trident owned by Ulysses S. Grant until his death.

Reference

 * Assassin's Creed: Last Descendants