Alric: "Ah, Sinis! I thought you died when Mazzarin collapsed the Shrine of Nyx upon you."
Sinis: "Indeed Alric, then I'll wager that you thought you'd seen the last of me!"
Alric: "I have seen the last of you."
Boom Boom Boom BOOM
If we assume that a Shade is a ressurected mage in that they are animated bodies and since having the old memories, their personality and knowledge remains unchanged (except of course they're evil) and thus appear to be truly reborn, when in fact the have no actual soul.
The thought then came to me, If a shade can be ressurected from a dead mage why, as long as the body isn't too damaged, not ressurect a dead Shade after he has been killed. Thus you can bring back a Shade over and over again as long as you have the body in good enough condition.
Thus we can assume that the afterlife of the Shade Sinis may have followed a pattern of:
Sinis is Shadafied and put under the control of The Deciever.
In one of the many Dec V Watcher battles Sinis fights the shade Mazzarin (whether you believe that Mazzarin is THE Mazzarin or just a shade named Mazzarin makes no difference here.) Mazzarin kills Sinis.
Myrdred finds Sinis' body and re-ressurects it.
Sinis faces Alric.
Sinis' comments "you thought you'd seen the last of me!" is in effect saying "If you kill me I'll be back again and again." Of course when Alric turns him into Shade pâté it makes his third (or fourth or fifth or...) coming impossible.
-zeph