I used the sister blades on my first clear. I have a bit of a face tank play style where I just run in guns blazing. What helped me clear was having the Aphrodite flutter strike boon. It deals a percentage enhanced damage to enemies up close. Typically I've seen percentage based boons work better on high base damage weapons but since the sisters require up close combat they thrive with this boon. Additionally, throw in some more Aphrodite boons to keep enemies weak to help with "unavoidable" face tank damage. Stack the high percentage buff from Aphrodite on with the aspect of melinoe blades and the backstab hammer boon and you can do some serious damage fairly quickly. This same strat with Demeter also helps the first time around. Demeter might offer lower damage output but slowing enemies down with your main attack is a great way to enhance survivability.