Mesmer boss

Im trying to kill Siska Scalewand or Talous the Mad for get a nice illusion staf for my mesmer, I can kill Siska whit my ranger (poison mainly) buy is very slow.

If anyone can suggest a build for farming these boss, will be very nice, coz no one solo mesmer bosses.

Thx you =)

mmm... no ideas?
Well, a star: Is possible kill Siska whit: poison arrow, hunter shot, distracting shot, ping down, storm chaser, troll unguent, read the wind and and free slot, maybe whirling defense.
First u kill the Siska friends, and then her. Is a lil slow, coz u must clean Nagas and some carpe, monk, ritu moobs one by one. I have kill Siska for 5 times just now, but no green drop
If u can imagine a fast way to kill her.
Sorry my english is very short.
Greetings. =)

Sabrina