I've seen the "Dark Shade" skill occasionally used on duelling builds, because it deals a bit more dmg than Shadow Image and the teleport isn't neccessary there (it is not targetable tho). But with all those recent and upcoming changes to it's dmg i'm not sure if it will still be worth slotting for that purpose. I also don't know how well it works against very mobile targets - it might get kited.
Combining it with Shadowrend is possible ofc, but kinda redundant, because both serve a very similar purpose (applying minor maim, proccing necro, bit of extra pressure).