Build for Demonslayer set?

Got this drop last night and I was wondering how one could make a build for it.’s-Life-Ender

A lot of the set bonuses seem geared towards phantasmal blades and other skills in the nightblade tree. However, the proc is based off autoattacking, so if I’m supposed to use Phantasmal Blades as my main attack how would I ever trigger this?

Any thoughts on playstyle surrounding this set?