Maya feels more like a catalyst to the saga rather than a major antagonist, she will probably have a big role in the saga later on but not on the level of what the outer Nine will be. The outer Nine will probably be more antagonistic than Maya. Speaking of, I have seen people say that Maya should have died in Echoes, however I think it was good that she survived ignoring the execution of the ending. This led to not only a new saga about humanity’s fated extinction, but also made the Vex more interesting. The TFS episodes are not great in execution, but I like how they set up the featured races and their evolution. The Choral Vex have gained sentience and individuality while becoming more strategic, Skolas can still revive himself and is will most likely lead the Revenant Scorn from now on, and a new entity is creating new Dire Taken.