Amazing for QD and beats Garuda+1 for Wildfire...theoretically you could use this over Arvina+1 too, so for Leaden as well, but it's not exactly a deal breaker. 7/10
If not at capped delay this ring is pretty great for melee tp phase over Rajas; it also comes with a top tier racc and amazing snapshot. Likely the ideal choice for someone who focuses on cor mainly. 9/10.
It's good for Last Stand, but not fantastic, overall could be skipped for better things. 6/10
Everything else ignore it...not that they're bad, but they shouldn't be your first thoughts when you play cor. Still Weatherspoon is a great casting ring, Janniston as cure pot piece, Gorney as lolTH...don't even look at the rest, it does nothing on this job.
tldr: if chosing based on cor, my suggestion is Haverton.