I prefer the incarnate over the widow by a long shot.. no comparison hands down incarnate is better.... you can summon and buff it on your first turn.. or even outside of combat... and it has wayyy more abilities than the widow and has aoe which the widow does not... on top of that the incarnate has opportunist talent and auto attacks people who try to run from him for even more damage... all the spider can do is auto attack single target and then die to all the magic cc being thrown its way that it has absolutely no defense against... and you can give the incarnate a teleport ability as well... there is literally no situation where the spider is better... it will spend the majority of every fight CCed by the many enemies who can shock/freeze people.