I believe Silent Dusk is a SCHs only ability to interrupt a mob. Sadly, it's underused because it can only interrupt spell-type abilities; other jobs have the ability to silence and have easier access to it; it shares the cooldown with Whispering Dawn, and Eos is just better because she brings more useful utility.

My proposition, and I know several will think I'm crazy, but I say get rid of the two fairy mechanic. The pet hotbar has four vacant slots. Eliminate Eos/Selene, and just give us Lily who has all of their abilities. This will likely never happen, and I suppose that's ok. Selene will simply remain my soloing fairy, or my 'we-are-all-overgeared-for-this-dungeon' fairy.