I think that part of the reason why people aren't overly impressed by Living Shadow is because its set rotation doesn't really make a lot of sense. It would be one thing if it charged in and performed a single target burst window with Delirium and Bloodspillers, but this thing uses AoE moves even in single target. It's just a random series of moves.

I'd almost argue that it would come across as more competent if it always behaved as if it were in single target. It seems like a confused AI sidekick, and players tend to be suspicious of confused AI sidekicks. Especially when they have the potential to go wandering off if you don't babysit them.

There's also the question of why the shadow needs to function like a pet at all. It would be one thing if it could, say, tank for a limited period of time (perhaps sharing HP with you). In the absence of that, it really just needs to be a well-animated, hard hitting oGCD dot. You could even condense the whole thing down and make the shadow attack much faster for effect.