i would go with scyl, bad el, archmage, doom priest and riho. i would put doompriest with very fast speed to help your team to stay alive with the help of archmage, and when the purples come i would nuke riho in first place and bad el as second, after the enemy dupes are off, you can just click auto.

Key to defeating Dark Fae in my setup is a two-fold approach..

1.) Be able to nuke your own team within the first round.

2.) Do not let Dark Fae get a turn....reduce her turn meter frequently 

The first one you can build up to be possible....for the second step...I do not know whether double Armiger will work sufficiently.

A good addition might be Visix once you get her...but Alure rules for this boss...

Matrim is spot on here, i run alure and visix to stop her getting another turn.

Armiger is probably your best bet for now, but i dont know if it will work

Thank You. Have tried a couple of builds based on your suggestions and had some success. It's not 100% yet, I think that's because of gear for most champs is not good enough. I'll have to fine-tune it a bit. 

At least now I have some idea of how to get it to 100% based on your suggestions. Thank you.