Three Kiels = 90% of the after-cast skill delay removed, and you could use another one, or 2 Expert Rings(5% per(?))
Three / Four Berzebub's would give it basically insta cast for skills like Twilight Alchemy that have a set cast no matter your DEX.
I could be wrong and the entire skill is based on After-cast delay instead of a fixed cast. *shrugs*