In the world of Remnant, the Faunus face oppression, deportation and subjugation at the hands of humanity. After a young Sienna Khan’s ambitious miners revolt ended in calamity she was pulled from the ruins by Kali of the resistance and her childhood friend, Ghira. With humanities war against the Faunus entering a new stage with Dr Merlot’s terrible machines of war, these young heroes may end up being all that stands between their people and being consigned to certain doom on Menagerie.

I can see your ambitious plot but you need to clear out your idea first. The previous one lacked specifics and this overloads it. Apply geometric mean. Something like:

When machine-powered Remnants repress and diminish his conventional-tribe, Faunus, a young valiant Faun must form an alliance to defend/ fight for his race.

Again the version I stated may or may not represent your idea but at least you have an idea, as where you can make cuts in your logline description.

When humans unleash terrifying machines to wipe out her entire species, an ambitious young native must rally her people and lead them in the battle for survival.

As CraigDGriffiths said,? the logline is lost in the 1st act.? I have no idea what the plot is.? Simplify, simplify.

And loglines for fictional stories do not include the names of characters.? More important than character names are defining characteristics.