I love Rescue! It's my favourite spell and has helped me save so many disasters it's not even funny!
That being said, Rescue is extremely unresponsive and difficult to use right.

Its biggest problem being the delay between casting it and pulling occurring. The thing about Rescue is that it's one of those spells that you need to anticipate and cast moments before you need it. If you need it, and THEN cast it, chances are the delay will mess it up and the player you're rescuing will be forced to their deaths.
That, too, has happened on many occasions.
I'm fine with the pulling, but I'd have liked for Rescue to start the pull the moment I hit the button instead of ~1.2s after the initial cast. Unlike the boss encounters in this game, players aren't predictable enough to adequately plan your Rescue that far ahead of time; to me, it feels like a strictly reactive spell when you can see that something is moments away from going wrong. It's just by the time you see it about to go wrong, it's usually too late.

At least that's how I feel about it!