Sort of but not really - they get the damage boost from Slow Time, but they don't count as being cast, so you have to cast some of your own to reduce the cooldown of Slow Time. The only reason I'd use etched sigil + disintegrate is because I'm lazy and the damage boost from deathwish/mantle of channeling/twisted sword/slow time all stack. You could easily just use ETwister instead with Ranslor's/twisted sword and the rune to make them merge, and use a generator; though I believe overall, unstable scepter + triumvirate is better.