This boss initially comes with 2 adds (4 in 25man). These 2 adds deal a lot of damage and hence must be burned down before focusing on the boss. Once these adds are down the boss herself is rather manageable, with mainly 3 abilities to watch out for.
The first ability is her AoE Fear. Fear Ward is useful and being immune to fear can mean extra healing or DPS time. However Fear Ward cannot block every single fear, but luckily the duration of the fear is relatively short and the boss doesn't immediately attack after a fear.
The second ability is Sonic Screech. This ability deals massive damage that is shared evenly among all players standing in front of the boss. Soloing this boss means taking to full 10 man's share of the damage. When using this ability the boss always faces the player and any attempts to run behind the boss does not work. Thus this damage is unavoidable.
The last ability to watch out for is that the boss occasionally summon another Feral Defender add into the fight. The add will initially pounce, stunning the player for a brief period, but aside from that the add does relatively minor damage. Killing the add will drop a void zone on the ground as well as further reduces the damage done by the next summoned feral defender.
Overall, the hardest part about this boss is probably the pull. Once the initial 2 adds are down, the boss herself becomes quite straightforward. Watch timers for her abilities (especially Sonic Screech) and use cooldowns accordingly.