Rajis does her damage mostly through water based spells. Use anti-caster or stun-lock abilities in order to keep her from casting. Occasionally she will knockback her target straight up into the air. (If you are in her hut, you'll just bounce off the ceiling) Also occasionally she'll summon a water elemental which can be crowd controlled. When Rajis has less than 2000 health left, she will try to run. Make sure you do not let her run into any other hostiles unless you can handle defeating them.