I should probably provide a bit more backround on the AU, huh?
Let me see...
one year prior to the RP, simultaneous with this universes version of the events of the show, the first year team WGRN were, for unknown reasons, targeted by a terrorist group known as world tree. over the course of several months, they fought off various attempts by the organization to kill them and attack Beacon, culminating in a battle in the forest of forever fall(about a month after the Vytal festival) after the teacher Grey was severely injured protecting his son from a previous attack. during the final battle, the leader of world tree was killed, while the other two members were incarcerated.

other events occurred during this time, including a mission following the events of Breach where the then 2nd year team VLCN were dispatched to secure Mountain Glen and clear the Grimm infestation in order to collapse the remaining tunnel systems and prevent another incident.

Finally, a massive swarm of aquatic Grimm of unknown species attacked the Vacuo coast, the effort to eliminate them was spearheaded by the students of the lesser academy known as Harbor(located on Vacuo's northern shore), particularly the first year team LZRT, several members of which came from one of the villages that was initially targeted by the Grimm later dubbed 'leviathan spawn'

the Mountain Glen reclamation mission and Leviathan Spawn invasion are common knowledge in the kingdoms in which they occurred (Vale and Vacuo, respectively) however World Tree was kept under wraps due to meddling by certain interested parties.

after World Tree was defeated, a high-profile assassin was hired to eliminate several notable figures residing within Beacon. due to a run of good fortune, he was disarmed and defeated by an unidentified team of veteran hunters. the assassins status is currently unknown.
and thats as much background as i can give without spoiling anything important.